do lcd displays update pixel by pixel free sample

Many Apple products use liquid crystal displays (LCD). LCD technology uses rows and columns of addressable points (pixels) that render text and images on the screen. Each pixel has three separate subpixels—red, green and blue—that allow an image to render in full color. Each subpixel has a corresponding transistor responsible for turning that subpixel on and off.

Depending on the display size, there can be thousands or millions of subpixels on the LCD panel. For example, the LCD panel used in the iMac (Retina 5K, 27-inch, 2019) has a display resolution of 5120 x 2880, which means there are over 14.7 million pixels. Each pixel is made up of a red, a green, and a blue subpixel, resulting in over 44 million individual picture elements on the 27-inch display. Occasionally, a transistor may not work perfectly, which results in the affected subpixel remaining off (dark) or on (bright). With the millions of subpixels on a display, it is possible to have a low number of such transistors on an LCD. In some cases a small piece of dust or other foreign material may appear to be a pixel anomaly. Apple strives to use the highest quality LCD panels in its products, however pixel anomalies can occur in a small percentage of panels.

In many cases pixel anomalies are caused by a piece of foreign material that is trapped somewhere in the display or on the front surface of the glass panel. Foreign material is typically irregular in shape and is usually most noticeable when viewed against a white background. Foreign material that is on the front surface of the glass panel can be easily removed using a lint free cloth. Foreign material that is trapped within the screen must be removed by an Apple Authorized Service Provider or Apple Retail Store.

If you are concerned about pixel anomalies on your display, take your Apple product in for closer examination at an Apple Store, Apple Authorized Service Provider, or an Independent Repair Provider. There may be a charge for the evaluation. Genuine Apple parts are also available for out-of-warranty repairs through Self Service Repair.*

Liquid crystal displays (LCDs) are comprised of tiny elements of color called pixels. Pixels have dimensions of a few microns or less and consist of three subpixels colored red, green, and blue. The popular acronym, RGB, is often used to delineate the color of a specific pixel within 16.7 million different color combinations. These tiny pixels are densely packed into television screens, computer monitors, tablets, and phones that utilize backlighting to illuminate each pixels and create the complex patterns we recognize as graphics and images today.

Figure 2:The six primary components of an liquid crystal display: 1. polarizing film, 2. electrode, 3. liquid crystal layer, 4. second electrode, 5. second polarizing film, 6. mirror or backlight. Image courtesy of Wikipedia under GNU Free Documentation License.

The most important concept in LCD technology is the behavior of liquid crystals. A twisted nematic liquid crystal layer acts to rotate (twist) the plane of polarization to align or misalign with the second polarizer. This means that if the polarizers are 90 degrees apart (see Figure 3, 4), then the twisted crystals will align with the second polarizer and permit light to pass through. Conversely, if the crystal layer did not exist, light would not pass through because the polarizers are oriented in such a way that the second polarizer blocks the light from the first polarizer.

Electrodes in LCDs function as on and off switches. The electrodes tune their voltage from on to off in 256 increments for each RGB subpixel. This is what gives 16.7 million different colors for each pixel (3 pixels, each with 256 shades; 2 raised to the 24th power).

In more primitive LCDs like those in digital watches or calculators, mirrors are used to reflect natural light to produce the digits we see on the displays. For more modern, high-power screens like TVs and laptops, backlights are used to illuminate the pixels. The backlights are often rectangles or strips of flourescent lamps or light emitting diodes (LEDs).

The most elementary concept of a computer screen lies in the manipulation of light. The goal here was to provide a simple overview of the primary components of a liquid crystal display (LCD) and its deceptive mechanics. Often, LCDs are thought of as complex systems not worth understanding, when in reality, an LCD consists most primitively of six parts: two polarizers, two electrodes, a liquid crystal layer, and a backlight or mirror. Once these mechanisms are understood, the complexity of a LCD remains in the deception of the human eye - not in the nature of its physics.

Dell offers a Premium Panel Exchange that ensures zero bright pixel defects on Dell Consumer, Professional, UltraSharp, and Gaming including Alienware monitors.

Defective pixels do not necessarily impair the performance of the monitor. However,they can be distracting, especially if the pixels are in positions where viewing quality is reduced.

Unyielding commitment to quality and customer satisfaction has driven Dell to offer a Premium Panel Exchange as part of the standard limited hardware warranty. Even if one bright pixel is found, a free monitor exchange is supported during the limited hardware warranty period.

Google"s Pixel 7 and 7 Pro both support face unlock, unlike last year"s Pixel 6 and Pixel 6 Pro. If you own a Pixel 7 and haven"t set it up yet, you can do so by launching the Settings menu and tapping Security. Tap Face and fingerprint unlock and enter your PIN. From there, choose the Face Unlock option to register your face to your phone.

We"ve all been there. It"s 6 a.m., your alarm starts blaring and you barely have the energy to reach for your phone. Google makes this a little easier on the Pixel lineup by enabling you to pause or dismiss an alarm by simply saying, "Snooze" or "Stop" without requiring the "Hey, Google" trigger phrase. You can do the same for phone calls by saying "Answer" or "Decline" without having to grab your device.

Both of these features are accessible from the Pixel"s phone app. Hold For Me works on the Pixel 3 and later, while Direct My Call is available on the Pixel 3A and later. Open the Phoneapp and tap the three dots in the top right corner to get started. Choose Settings and you should see Hold for Me and Direct My Call under the Assistive section.

Certain Pixel devices can boost their refresh rates to enable faster scrolling and smoother animations, which makes the software generally feel more responsive. The Pixel 7 can bump its refresh rate up to 90Hz like the Pixel 6, while the Pixel 7 Pro can go up to 120Hz just like the Pixel 6 Pro. But since this feature increases battery usage, there are times when you might want to turn it off.

The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by different factors in cathode ray tube (CRT) displays, flat-panel displays (including liquid-crystal displays) and projection displays using fixed picture-element (pixel) arrays.

It is usually quoted as width × height, with the units in pixels: for example, 1024 × 768 means the width is 1024 pixels and the height is 768 pixels. This example would normally be spoken as "ten twenty-four by seven sixty-eight" or "ten twenty-four by seven six eight".

One use of the term display resolution applies to fixed-pixel-array displays such as plasma display panels (PDP), liquid-crystal displays (LCD), Digital Light Processing (DLP) projectors, OLED displays, and similar technologies, and is simply the physical number of columns and rows of pixels creating the display (e.g. 1920 × 1080). A consequence of having a fixed-grid display is that, for multi-format video inputs, all displays need a "scaling engine" (a digital video processor that includes a memory array) to match the incoming picture format to the display.

For device displays such as phones, tablets, monitors and televisions, the use of the term display resolution as defined above is a misnomer, though common. The term display resolution is usually used to mean pixel dimensions, the maximum number of pixels in each dimension (e.g. 1920 × 1080), which does not tell anything about the pixel density of the display on which the image is actually formed: resolution properly refers to the pixel density, the number of pixels per unit distance or area, not the total number of pixels. In digital measurement, the display resolution would be given in pixels per inch (PPI). In analog measurement, if the screen is 10 inches high, then the horizontal resolution is measured across a square 10 inches wide.NTSC TVs can typically display about 340 lines of "per picture height" horizontal resolution from over-the-air sources, which is equivalent to about 440 total lines of actual picture information from left edge to right edge.

Some commentators also use display resolution to indicate a range of input formats that the display"s input electronics will accept and often include formats greater than the screen"s native grid size even though they have to be down-scaled to match the screen"s parameters (e.g. accepting a 1920 × 1080 input on a display with a native 1366 × 768 pixel array). In the case of television inputs, many manufacturers will take the input and zoom it out to "overscan" the display by as much as 5% so input resolution is not necessarily display resolution.

The eye"s perception of display resolution can be affected by a number of factors – see image resolution and optical resolution. One factor is the display screen"s rectangular shape, which is expressed as the ratio of the physical picture width to the physical picture height. This is known as the aspect ratio. A screen"s physical aspect ratio and the individual pixels" aspect ratio may not necessarily be the same. An array of 1280 × 720 on a 16:9 display has square pixels, but an array of 1024 × 768 on a 16:9 display has oblong pixels.

An example of pixel shape affecting "resolution" or perceived sharpness: displaying more information in a smaller area using a higher resolution makes the image much clearer or "sharper". However, most recent screen technologies are fixed at a certain resolution; making the resolution lower on these kinds of screens will greatly decrease sharpness, as an interpolation process is used to "fix" the non-native resolution input into the display"s native resolution output.

While some CRT-based displays may use digital video processing that involves image scaling using memory arrays, ultimately "display resolution" in CRT-type displays is affected by different parameters such as spot size and focus, astigmatic effects in the display corners, the color phosphor pitch shadow mask (such as Trinitron) in color displays, and the video bandwidth.

Most television display manufacturers "overscan" the pictures on their displays (CRTs and PDPs, LCDs etc.), so that the effective on-screen picture may be reduced from 720 × 576 (480) to 680 × 550 (450), for example. The size of the invisible area somewhat depends on the display device. Some HD televisions do this as well, to a similar extent.

Computer displays including projectors generally do not overscan although many models (particularly CRT displays) allow it. CRT displays tend to be underscanned in stock configurations, to compensate for the increasing distortions at the corners.

Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. This enhances motion perception to the viewer, and reduces flicker by taking advantage of the phi phenomenon.

The European Broadcasting Union has argued against interlaced video in production and broadcasting. The main argument is that no matter how complex the deinterlacing algorithm may be, the artifacts in the interlaced signal cannot be completely eliminated because some information is lost between frames. Despite arguments against it, television standards organizations continue to support interlacing. It is still included in digital video transmission formats such as DV, DVB, and ATSC. New video compression standards like High Efficiency Video Coding are optimized for progressive scan video, but sometimes do support interlaced video.

Many personal computers introduced in the late 1970s and the 1980s were designed to use television receivers as their display devices, making the resolutions dependent on the television standards in use, including PAL and NTSC. Picture sizes were usually limited to ensure the visibility of all the pixels in the major television standards and the broad range of television sets with varying amounts of over scan. The actual drawable picture area was, therefore, somewhat smaller than the whole screen, and was usually surrounded by a static-colored border (see image below). Also, the interlace scanning was usually omitted in order to provide more stability to the picture, effectively halving the vertical resolution in progress. 160 × 200, 320 × 200 and 640 × 200 on NTSC were relatively common resolutions in the era (224, 240 or 256 scanlines were also common). In the IBM PC world, these resolutions came to be used by 16-color EGA video cards.

One of the drawbacks of using a classic television is that the computer display resolution is higher than the television could decode. Chroma resolution for NTSC/PAL televisions are bandwidth-limited to a maximum 1.5MHz, or approximately 160 pixels wide, which led to blurring of the color for 320- or 640-wide signals, and made text difficult to read (see example image below). Many users upgraded to higher-quality televisions with S-Video or RGBI inputs that helped eliminate chroma blur and produce more legible displays. The earliest, lowest cost solution to the chroma problem was offered in the Atari 2600 Video Computer System and the Apple II+, both of which offered the option to disable the color and view a legacy black-and-white signal. On the Commodore 64, the GEOS mirrored the Mac OS method of using black-and-white to improve readability.

The 640 × 400i resolution (720 × 480i with borders disabled) was first introduced by home computers such as the Commodore Amiga and, later, Atari Falcon. These computers used interlace to boost the maximum vertical resolution. These modes were only suited to graphics or gaming, as the flickering interlace made reading text in word processor, database, or spreadsheet software difficult. (Modern game consoles solve this problem by pre-filtering the 480i video to a lower resolution. For example, Final Fantasy XII suffers from flicker when the filter is turned off, but stabilizes once filtering is restored. The computers of the 1980s lacked sufficient power to run similar filtering software.)

In the PC world, the IBM PS/2 VGA (multi-color) on-board graphics chips used a non-interlaced (progressive) 640 × 480 × 16 color resolution that was easier to read and thus more useful for office work. It was the standard resolution from 1990 to around 1996.800 × 600 until around 2000. Microsoft Windows XP, released in 2001, was designed to run at 800 × 600 minimum, although it is possible to select the original 640 × 480 in the Advanced Settings window.

Programs designed to mimic older hardware such as Atari, Sega, or Nintendo game consoles (emulators) when attached to multiscan CRTs, routinely use much lower resolutions, such as 160 × 200 or 320 × 400 for greater authenticity, though other emulators have taken advantage of pixelation recognition on circle, square, triangle and other geometric features on a lesser resolution for a more scaled vector rendering. Some emulators, at higher resolutions, can even mimic the aperture grille and shadow masks of CRT monitors.

The availability of inexpensive LCD monitors made the 5∶4 aspect ratio resolution of 1280 × 1024 more popular for desktop usage during the first decade of the 21st century. Many computer users including CAD users, graphic artists and video game players ran their computers at 1600 × 1200 resolution (UXGA) or higher such as 2048 × 1536 QXGA if they had the necessary equipment. Other available resolutions included oversize aspects like 1400 × 1050 SXGA+ and wide aspects like 1280 × 800 WXGA, 1440 × 900 WXGA+, 1680 × 1050 WSXGA+, and 1920 × 1200 WUXGA; monitors built to the 720p and 1080p standard were also not unusual among home media and video game players, due to the perfect screen compatibility with movie and video game releases. A new more-than-HD resolution of 2560 × 1600 WQXGA was released in 30-inch LCD monitors in 2007.

In 2010, 27-inch LCD monitors with the 2560 × 1440 resolution were released by multiple manufacturers, and in 2012, Apple introduced a 2880 × 1800 display on the MacBook Pro. Panels for professional environments, such as medical use and air traffic control, support resolutions up to 4096 × 21602048 × 2048 pixels).

In this image of a Commodore 64 startup screen, the overscan region (the lighter-coloured border) would have been barely visible when shown on a normal television.

In recent years the 16:9 aspect ratio has become more common in notebook displays. 1366 × 768 (HD) has become popular for most low-cost notebooks, while 1920 × 1080 (FHD) and higher resolutions are available for more premium notebooks.

When a computer display resolution is set higher than the physical screen resolution (native resolution), some video drivers make the virtual screen scrollable over the physical screen thus realizing a two dimensional virtual desktop with its viewport. Most LCD manufacturers do make note of the panel"s native resolution as working in a non-native resolution on LCDs will result in a poorer image, due to dropping of pixels to make the image fit (when using DVI) or insufficient sampling of the analog signal (when using VGA connector). Few CRT manufacturers will quote the true native resolution, because CRTs are analog in nature and can vary their display from as low as 320 × 200 (emulation of older computers or game consoles) to as high as the internal board will allow, or the image becomes too detailed for the vacuum tube to recreate (i.e., analog blur). Thus, CRTs provide a variability in resolution that fixed resolution LCDs cannot provide.

As far as digital cinematography is concerned, video resolution standards depend first on the frames" aspect ratio in the film stock (which is usually scanned for digital intermediate post-production) and then on the actual points" count. Although there is not a unique set of standardized sizes, it is commonplace within the motion picture industry to refer to "nK" image "quality", where n is a (small, usually even) integer number which translates into a set of actual resolutions, depending on the film format. As a reference consider that, for a 4:3 (around 1.33:1) aspect ratio which a film frame (no matter what is its format) is expected to horizontally fit in, n is the multiplier of 1024 such that the horizontal resolution is exactly 1024•n points.2048 × 1536 pixels, whereas 4K reference resolution is 4096 × 3072 pixels. Nevertheless, 2K may also refer to resolutions like 2048 × 1556 (full-aperture), 2048 × 1152 (HDTV, 16:9 aspect ratio) or 2048 × 872 pixels (Cinemascope, 2.35:1 aspect ratio). It is also worth noting that while a frame resolution may be, for example, 3:2 (720 × 480 NTSC), that is not what you will see on-screen (i.e. 4:3 or 16:9 depending on the intended aspect ratio of the original material).

The Pixel 5 isn"t quite worth its high price, especially since its software support window ends soon (October 2023). Amazon currently sells the Pixel 4A 5G for the same price as the Pixel 6A, and while it"s a good phone, it should be cheaper. You"re better off sticking with the Pixel 6A. As for older Pixels, they"re not worth picking up. They"re just too old (and the Pixel 4 suffers from poor battery performance). Many of those devices will stop getting software updates soon if they haven"t already. Buy one of the newer models.

The revamped case for the Pixel 7 series feels more durable than ever before, and you can match them with your Pixel"s color. The thermoplastic elastomer feels nice to touch, and there are raised edges on the front to protect the screen. The Pixel 7"s case is made with more than 30 percent recycled plastics, and the polycarbonate shell uses 77 percent recycled plastics. There are metal buttons for power and volume and they"re 100 percent recycled aluminum. The cases for the Pixel 6 and Pixel 6A are similar but slightly different.

This is hands-down the best case if you frequently attach your Pixel to the handlebar of a bike or electric scooter. Peak Design"s mounting system lets you magnetically affix the phone to its Universal Bike Mount ($50) and it stays put—after nearly a year of testing, I"ve yet to have a phone fall off my ride using this mounting system. It doesn"t interrupt the Pixel"s wireless charging either. The company has several other magnetic accessories you can use, like a car mount. The case itself is nice; I just wish the edges were raised a bit more for better screen protection.

This is one of the best clear cases you"ll find, especially at this price, for the Pixel. The buttons are clicky, the Pixel"s color comes through clearly, and the rear doesn"t feel too sticky, which can be a problem with some clear cases.Caseology Tempered Glass Screen ProtectorPhotograph: Caseology

Pixel phones don"t have a great track record with screen durability—they scratch easily. We tested this protector originally for the Pixel 5A, but it"s not available anymore. Caseology does sell it now for the Pixel 7, Pixel 6, and Pixel 6A. Installation is easy, and it includes a squeegee to get rid of air bubbles. You get two screen protectors for the price, including a microfiber cloth, a wipe, and dust removal stickers.

This is another easy-to-apply tempered glass screen protector. The Pixel 7 and Pixel 6 version comes with two protectors, but Spigen only includes one for the Pixel 6A. Boo. You get a whole cleaning kit to wipe down your phone, an alignment tool that helps you get the application right, and a squeegee to get rid of the air bubbles.

You get only one screen protector here and it"s very expensive. That"s because Zagg claims that the protector is five times as strong as traditional screen protectors. I haven"t seen too many scuffs on my Pixel 6A yet, but take this with a grain of salt. It"s easy to apply with the included application tool, but Zagg doesn"t include a squeegee at this price so you"ll have to use your fingers to push the air bubbles out. It comes with a dust sticker, a wet wipe, and a microfiber cloth.Google Pixel Stand (Gen 2)Photograph: Google

Of the Pixels we recommend in this guide, wireless charging is available only on the Pixel 6, Pixel 6 Pro, Pixel 7, and Pixel 7 Pro. Google"s very own Pixel Stand is one of the best wireless chargers around because it"s simple. The base doesn"t slide around, the phone stays put, and it enables some fun features, like turning the screen into a digital photo frame and quick access to Google Assistant. It"s made of 39 percent recycled materials, with mostly eco-friendly packaging too. Our Best Wireless Chargers guide has more options. It"s also available at Best Buy.

This charging adapter is all you need to recharge your Pixel, whichever model you have. The newest high-end Pixel phones don"t come with chargers in the box, so if you don"t have any spare USB-C chargers, it"s worth picking one up. This one"s prongs don"t fold up, but it"s still really compact.

These cases are pricey, but they have raised lips and offer decent protection around the edges. The buttons are clicky, and you get a few designs to choose from for the rear, including walnut, leather, bamboo, silver pearl, and aramid fiber. (I love the walnut.) What makes this case special is that it supports MagSafe—yes, Apple"s magnetic system for accessories. I"ve used the Mous Limitless 5.0 successfully with a few MagSafe accessories, like a Belkin wireless charger, to recharge the Pixel 7 Pro. You can also go with Mous" IntraLock case to use the company"s own magnetic accessory system to hook your phone up to its bike or car mount with more security.Photograph: Spigen

It"s slim, has a nice texture, retains clicky buttons, and has accurate cutouts for the ports and speakers. What"s not to love? Well, it"s a bit dull, but I still think this case is one of the more attractive cases in Spigen"s lineup. The edges aren"t raised drastically, so don"t expect much screen protection.

Want a kickstand to prop your Pixel up? This Spigen case has one built in and it does the trick, though unfortunately, you can keep your device up only in landscape mode—not great for hands-free TikTok. It has a thick bumper offering nice protection around the edges, though there"s not much of a lip sticking out, so you"ll still want to pair it with a screen protector.

Of all the Pixel cases I"ve tried, this feels the best. It has a wonderful texture that"s pleasant to touch, and the case keeps a slim profile. The buttons remain clicky, and the ports are well-exposed. It"s affordable, but the front edges aren"t raised. There"s a good chance the screen will hit the ground when you drop it.Photograph: Moment

The Pixels have great cameras, but you can take them further by using third-party lenses like these from Moment. Slap on a fish-eye lens for a fun, distorted photo effect. Use a 58-mm telephoto to get even closer to your subject. Whatever lens you pick, you"ll need a Moment case for the system to work. Unfortunately, the Pixel 7, Pixel 7 Pro, and Pixel 6A cases aren"t compatible with the lenses. Still, I like "em because they have magnets embedded inside—they"ll work with Moment"s various MagSafe mounts, like one for tripods, video lights, and mics.

It takes some effort to install this case on the Pixel, but once you do, it"s arguably the most protection you"ll find. There"s an inner two-piece polycarbonate shell that snaps over and under the Pixel, and then a thick synthetic rubber slipcover goes over for extreme durability. The buttons are surprisingly clicky, though the whole phone will be thicker, wider, and heavier. It"s made of more than 50 percent recycled plastic, and there"s a holster you can pop it in to carry your Pixel with pride on your belt. (The holster can double as a kickstand.)

There are some key features exclusive to Pixels that you won"t find on any other Android phone. Some of these are only available on select Pixels—the ones powered by Google"s Tensor chips are more capable since it"s the company"s own silicon. Here"s a quick breakdown:

The Service Contract Provider is Federal Warranty Service Corporation in all states except in California where the Provider is Sureway, Inc.; in Florida where the Provider is United Service Protection, Inc., and in Oklahoma where the Provider is Assurant Service Protection, Inc. Please see sample Terms and Conditions for full details on Obligors, benefits, limitations and exclusions. For the Preferred Care upfront plan, your device protection includes 1 year of mechanical breakdown coverage (after the one-year manufacturer warranty expires) and up to 2 accidental damage claims per coverage term or 2 in a rolling 12-month period or based on device. For the Preferred Care Monthly Coverage plan, your devices include 4 years of mechanical breakdown coverage (after the one-year manufacturer warranty expires) and up to 2 accidental damage claims in a rolling 12-month period beginning with the date of the first repair or replacement.

LCD panelscan be categorized as flat-panel displays. What makes them distinct from other display technologies is the layer of liquid crystal material within. In this thin layer, liquid crystal molecules are aligned between two glass substrates. On the inner surfaces of each of those substrates lie electrodes that control charge carriers like electrons that then interact with the liquid crystals, creating an electric field that runs through them; this, in turn, can change the alignment of the crystals, also changing the overall behavior of the molecules. On the opposite sides of the substrate, polarizers are used to control the levels of light passage, affecting the overall image of the display.

Unlike CRT monitors, LCD monitors cannot illuminate themselves, and so they require a light source: the backlight. This backlight is most frequently made of the well-known LEDs which stand for light-emitting diodes. Sourced from the backlight, light is moved through the back polarizer and back substrate, into the liquid crystals. Now, the light waves can behave in a variety of ways. Backlight used in LCD displays can be LED (Light Emitting Diode) backlight or CCFL (Cold Cathode Fluorescent Lamp) backlight. LED backlights use less power which becomes more popular, while CCFL is lower cost for large size LCD displays such as large LCD TV. Recently, quantum dots technology is used to increase the LCD contrast.

Electrodes are the controlling factors of the liquid crystal behavior, and thus also the light behavior. By conducting or not conducting a current into the crystal layer, the light may or may not be able to pass through the liquid crystals in a manner that will allow passage through the polarizer. Because of this role, electrodes in LCDs are often made of indium tin oxide (ITO). ITO has good conducting properties and can also make for a transparent electrode which is essential to the appearance of displays today.

How the electrodes affect the liquid crystal alignment can vary depending on the method of alignment used (twistednematic,multi-domain,in-planeswitching). For example, twisted nematic liquid crystals are oriented in a twist when no electric field is present which then polarizes the light passing through the layer; when the electrodes apply the field in full, the twist will straighten out, no longer polarizing the light, and so no light passes. In each of these alignment types, the electrodes are placed differently within the structure, altering the properties of the display, such as width of viewing angle, power consumption, and response time. Despite these different alignment methods, the liquid crystal layer’s purpose remains the same: to polarize the light so that the polarized light passes through to the surface of the display. By polarizing the light transmitted from the backlight, the liquid crystal molecules play a role in how much of the light passes through the polarizing filters, whether it be all, none, or a partial amount.

ATTENTION MAC USERS: Free & Clear does run on Macs under Virtual PC with Windows 95/98. I won"t be creating a Mac-specific version of the freeware demo, but you can see for yourself (from the samples above) how it looks on your Mac, and you can play with it if you have Virtual PC.

While the application of Sub-Pixel Graphic Rendering will absolutely benefit virtually all users of LCD displays, it"s important to understand that this technique is not applicable to high-resolution Cathode Ray Tube (CRT) displays. Yes, I know, the sample above looked really great on your CRT, but that"s mostly because any mature sub-pixel rendering technology also incorporates aspects of anti-aliasing (as we"ll see on the next page of this little web zone.) And it"s well known that anti-aliasing helps tremendously with the display of text. So even though sub-pixel rendering is better than nothing on CRT"s, its "colorized" aspects only really work on LCD displays.

As we"ve seen, the success of sub-pixel rendering depends upon using part of an adjacent pixel to extend an existing pattern of sub-pixels which the eye perceives as a slightly larger white or black pixel. While this approach can also be employed with low-saturation (pastel) colors, it will always be most effective when displaying high contrast white and black images. Dark colored text on a white background will be effective, as would white text on a dark colored background. But black & white best shows off what this technology can do.

As we"ve seen, sub-pixel rendering only enhances the horizontal resolution of LCD panels. It"s incredibly convenient that "horizontally" is precisely where text needs the most help! Emboldening stretches text only horizontally, kerning and micro-justification only shift text horizontally, and italicizing slants type by skewing it horizontally. However, this means that existing color LCD panel technology can not be used with sub-pixel text rendering when the panel is used in a vertical, or portrait, orientation.

It seems to me that this significantly cools off our excitement about the application of our existing hardware for eBooks, since eBooks utilize the traditional book"s familiar vertical orientation which is completely incompatible with existing color LCD construction for under sub-pixel rendering.

However, there is certainly nothing to prevent the creation of a new breed of LCD panels specifically for eBooks. They would be longer vertically than horizontally (for portrait orientation), while orienting their sub-pixels horizontally like existing LCD panels. Such a new style display would indeed be a fabulous eBook component since it could display color images clearly while simultaneously employing sub-pixel rendering for its page"s text.

Since a few LCD panels have their sub-pixels arranged in B-G-R instead of R-G-B order, any industrial strength delivery of sub-pixel rendering technology will require a user-settable (or operating system readable) option to inform the system"s LCD rendering engine whether the sub-pixels are arranged in "forward" or "reverse" order.

Windows apps can run on any device running Windows, which includes tablets, desktops, TVs, and more. With a huge number of device targets and screen sizes across the Windows ecosystem, rather than optimizing your UI for each device, we recommended designing for a few key width categories (also called "breakpoints"):

When designing for specific breakpoints, design for the amount of screen space available to your app (the app"s window), not the screen size. When the app is running full-screen, the app window is the same size as the screen, but when the app is not full-screen, the window is smaller than the screen.

While most TVs are physically quite large (40 to 65 inches is common) and have high resolutions (HD or 4k), designing for a 1080P TV that you view from 10 feet away is different from designing for a 1080p monitor sitting a foot away on your desk. When you account for distance, the TV"s 1080 pixels are more like a 540-pixel monitor that"s much closer.

XAML"s effective pixel system automatically takes viewing distance in account for you. When you specify a size for a control or a breakpoint range, you"re actually using "effective" pixels. For example, if you create responsive code for 1080 pixels or more, a 1080 monitor will use that code, but a 1080p TV will not--because although a 1080p TV has 1080 physical pixels, it only has 540 effective pixels. Which makes designing for a TV similar to designing for a small screen.

When your app runs on a device, the system uses an algorithm to normalize the way UI elements display on the screen. This scaling algorithm takes into account viewing distance and screen density (pixels per inch) to optimize for perceived size (rather than physical size). The scaling algorithm ensures that a 24 px font on Surface Hub 10 feet away is just as legible to the user as a 24 px font on 5" phone that"s a few inches away.

Because of how the scaling system works, when you design your XAML app, you"re designing in effective pixels, not actual physical pixels. Effective pixels (epx) are a virtual unit of measurement, and they"re used to express layout dimensions and spacing, independent of screen density. (In our guidelines, epx, ep, and px are used interchangeably.)

You can ignore the pixel density and the actual screen resolution when designing. Instead, design for the effective resolution (the resolution in effective pixels) for a size class (for details, see the Screen sizes and breakpoints article).

XAML scales across a range of devices with scaling plateaus of 100%, 125%, 150%, 175%, 200%, 225%, 250%, 300%, 350%, and 400%. The base unit is 4 because it can be scaled to these plateaus as a whole number (for example; 4 x 125% = 5, 4 x 150% = 6). Using multiples of four aligns all UI elements with whole pixels and ensures UI elements have crisp, sharp edges. (Note that text doesn"t have this requirement; text can have any size and position.)

This tutorial is from the book Learning Processing by Daniel Shiffman, published by Morgan Kaufmann, © 2008 Elsevier Inc. All rights reserved. If you see any errors or have comments, please let us know.

A digital image is nothing more than data—numbers indicating variations of red, green, and blue at a particular location on a grid of pixels. Most of the time, we view these pixels as miniature rectangles sandwiched together on a computer screen. With a little creative thinking and some lower level manipulation of pixels with code, however, we can display that information in a myriad of ways. This tutorial is dedicated to breaking out of simple shape drawing in Processing and using images (and their pixels) as the building blocks of Processing graphics.

In fact, the loadImage() function performs the work of a constructor, returning a brand new instance of a PImage object generated from the specified filename. We can think of it as the PImage constructor for loading images from a file. For creating a blank image, the createImage() function is used.// Create a blank image, 200 x 200 pixels with RGB color

We should also note that the process of loading the image from the hard drive into memory is a slow one, and we should make sure our program only has to do it once, in setup(). Loading images in draw() may result in slow performance as well as "Out of Memory" errors.

When displaying an image, you might like to alter its appearance. Perhaps you would like the image to appear darker, transparent, blue-ish, etc. This type of simple image filtering is achieved with Processing"s tint() function. tint() is essentially the image equivalent of shape"s fill(), setting the color and alpha transparency for displaying an image on screen. An image, nevertheless, is not usually all one color. The arguments for tint() simply specify how much of a given color to use for every pixel of that image, as well as how transparent those pixels should appear.

For the following examples, we will assume that two images (a sunflower and a dog) have been loaded and the dog is displayed as the background (which will allow us demonstrate transparency.)PImage sunflower = loadImage("sunflower.jpg");

If you"ve just begun using Processing you may have mistakenly thought that the only offered means for drawing to the screen is through a function call. "Draw a line between these points" or "Fill an ellipse with red" or "load this JPG image and place it on the screen here." But somewhere, somehow, someone had to write code that translates these function calls into setting the individual pixels on the screen to reflect the requested shape. A line doesn"t appear because we say line(), it appears because we color all the pixels along a linear path between two points. Fortunately, we don"t have to manage this lower-level-pixel-setting on a day-to-day basis. We have the developers of Processing (and Java) to thank for the many drawing functions that take care of this business.

Nevertheless, from time to time, we do want to break out of our mundane shape drawing existence and deal with the pixels on the screen directly. Processing provides this functionality via the pixels array.

We are familiar with the idea of each pixel on the screen having an X and Y position in a two dimensional window. However, the array pixels has only one dimension, storing color values in linear sequence.

Take the following simple example. This program sets each pixel in a window to a random grayscale value. The pixels array is just like an other array, the only difference is that we don"t have to declare it since it is a Processing built-in variable.size(200, 200);

First, we should point out something important in the above example. Whenever you are accessing the pixels of a Processing window, you must alert Processing to this activity. This is accomplished with two functions:loadPixels() This function is called before you access the pixel array, saying "load the pixels, I would like to speak with them!"

In the above example, because the colors are set randomly, we didn"t have to worry about where the pixels are onscreen as we access them, since we are simply setting all the pixels with no regard to their relative location. However, in many image processing applications, the XY location of the pixels themselves is crucial information. A simple example of this might be, set every even column of pixels to white and every odd to black. How could you do this with a one dimensional pixel array? How do you know what column or row any given pixel is in?

In programming with pixels, we need to be able to think of every pixel as living in a two dimensional world, but continue to access the data in one (since that is how it is made available to us). We can do this via the following formula:Assume a window or image with a given WIDTH and HEIGHT.

This may remind you of our two dimensional arrays tutorial. In fact, we"ll need to use the same nested for loop technique. The difference is that, although we want to use for loops to think about the pixels in two dimensions, when we go to actually access the pixels, they live in a one dimensional array, and we have to apply the formula from the above illustration.

The previous section looked at examples that set pixel values according to an arbitrary calculation. We will now look at how we might set pixels according those found in an existing PImage object. Here is some pseudo-code.Load the image file into a PImage object

Now, we could certainly come up with simplifications in order to merely display the image (for example, the nested loop is not required, not to mention that using the image() function would allow us to skip all this pixel work entirely.) However, example 15-7 provides a basic framework for getting the red, green, and blue values for each pixel based on its spatial orientation (XY location); ultimately, this will allow us to develop more advanced image processing algorithms.

Since we are altering the image on a per pixel basis, all pixels need not be treated equally. For example, we can alter the brightness of each pixel according to its distance from the mouse.

All of our image processing examples have read every pixel from a source image and written a new pixel to the Processing window directly. However, it"s often more convenient to write the new pixels to a destination image (that you then display using the image() function). We"ll demonstrate this technique while looking at another simple pixel operation: threshold.

A threshold filter displays each pixel of an image in only one of two states, black or white. That state is set according to a particular threshold value. If the pixel"s brightness is greater than the threshold, we color the pixel white, less than, black. In the code below, we use an arbitrary threshold of 100.

This particular functionality is available without per pixel processing as part of Processing"s filter() function. Understanding the lower level code, however, is crucial if you want to implement your own image processing algorithms, not available with filter().

In previous examples, we"ve seen a one-to-one relationship between source pixels and destination pixels. To increase an image"s brightness, we take one pixel from the source image, increase the RGB values, and display one pixel in the output window. In order to perform more advanced image processing functions, we must move beyond the one-to-one pixel paradigm into pixel group processing.

We could then make a new color out of the difference between the pixel and its neighbor to the left.float diff = abs(brightness(pix) - brightness(leftPix));

This example is a simple horizontal edge detection algorithm. When pixels differ greatly from their neighbors, they are most likely "edge" pixels. For example, think of a picture of white piece of paper on a black tabletop. The edges of that paper are where the colors are most different, where white meets black.

In the previous example, we looked at two pixels to find edges. More sophisticated algorithms, however, usually involve looking at many pixels at a time. After all, each pixel has 8 immediate neighbors: top left, top, top right, right, bottom right, bottom, bottom left, left.

These image processing algorithms are often referred to as a "spatial convolution." The process uses a weighted average of an input pixel and its neighbors to calculate an output pixel. In other words, that new pixel is a function of an area of pixels. Neighboring areas of different sizes can be employed, such as a 3x3 matrix, 5x5, etc.

Different combinations of weights for each pixel result in various effects. For example, we "sharpen" an image by subtracting the neighboring pixel values and increasing the center point pixel. A blur is achieved by taking the average of all neighboring pixels. (Note that the values in the convolution matrix add up to 1).

Following is an example that performs a convolution using a 2D array (see Chapter 13, p. XX for a review of 2D arrays) to store the pixel weights of a 3x3 matrix. This example is probably the most advanced example we"ve encountered in this book so far since it involves so many elements (nested loops, 2D arrays, PImage pixels, and so on.)

You may be thinking: "Gosh, this is all very interesting, but seriously, when I want to blur an image or change its brightness, do I really need to write code? I mean, can"t I use Photoshop?" Indeed, what we have achieved here is an merely an introductory understanding of what highly skilled programmers at Adobe do. The power of Processing, however, is the potential for real-time, interactive graphics applications. There is no need for us to live within the confines of "pixel point" and "pixel group" processing.

Following are two examples of algorithms for drawing processing shapes. Instead of coloring the shapes randomly or with hard-coded values as we have in the past, we select colors from pixels inside of a PImage object. The image itself is never displayed; rather, it serves as a database of information that we can exploit for a multitude of creative pursuits.

In this first example, for every cycle through draw(), we fill one ellipse at a random location onscreen with a color taken from its corresponding location in the source image. The result is a basic "pointillist-like" effect:

In this next example, we take the data from a two-dimensional image and using the 3D translation techniques described in chapter 14, render a rectangle for each pixel in three-dimensional space. The z location is determined by the brightness of the color. Brighter colors appear closer to the viewer and darker ones farther away.

Pixelmator Pro is an image editor designed to make the most powerful professional image editing tools accessible to everyone. And with an extensive collection of tools for editing and retouching photos, creating graphic designs, painting, drawing vector graphics, and adding stunning effects, it’s the only image editor you’ll need.

Pixelmator Pro 3.2 introduces some incredible new ways to create designs with full support for video layers, adds support for popular video formats, includes all-new video and social media templates, brings major improvements to Motion document support, and more.

The collection of powerful, nondestructive color adjustments in Pixelmator Pro lets you edit the colors in your photos, or even videos, in any way you want. And with full support for RAW photos, a collection of stunning adjustment presets, and incredible retouching tools, it couldn’t be easier to turn good-looking photos spectacular.

In Pixelmator Pro, you’ll find everything from essential color adjustments like brightness, contrast, and exposure to advanced tools like multi-channel curves and wheel-based color balance.

Magically remove unwanted objects, clone parts of your photos, lighten or darken precise areas, and do much more. All by using simple brushstrokes to retouch just the areas you want. So all your shots look picture-perfect.

Pixelmator Pro supports RAW photos from over 600 of the most popular digital cameras. What’s more, you can add RAW photos as RAW layers and edit directly without having to convert or preprocess them.

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The SVG vector file format is supported in Pixelmator Pro, so you can open SVG files, edit their shapes and paths, and export while keeping all their vector data.

Whether you’re working on a design for a poster, a webpage, or a blockbuster app, you’ll make your ideas come to life in Pixelmator Pro. With smart spacing guides, advanced alignment tools, and blazing fast performance, you can harness the full power of layer-based editing.

Use simple buildings blocks – shape, text, video, and image layers – to create stunning compositions and designs. Add layers in delightfully quick and simple ways, such as by dragging and dropping them straight into Pixelmator Pro, or using the built-in Photo Browser.

The Arrange tool makes it incredibly easy to create designs. It lets you automatically select layers by clicking them on the canvas, intelligently snaps layers into position as you move them around, and even lets you align and distribute layers automatically.

Nondestructively customize the look of any layer in your image by adding fills, strokes, and shadows, or any combination of multiple styles. And with presets, you can save your favorite combinations, use them in any of your images, and even share them with others.

Pixelmator Pro includes a stunning collection of handcrafted dual-texture brushes, full graphics tablet support, and advanced paint blending technologies. A cutting edge painting engine powered by Metal, the advanced graphics acceleration technology created by Apple, delivers incredible performance.

Pixelmator Pro includes a stunning collection of over 100 handcrafted, dual texture brushes — choose from a dazzling array of gorgeous paintbrushes, watercolors, markers, pencils, crayons, basic brushes, and more.

Use the Pixel Tool to create awesome pixel art. It automatically lines up each pixel you place on the canvas, no matter how big or small the pixels are. Creating pixel-perfect art couldn’t be simpler.

Customize the Pixelmator Pro workspace to make it work for you — move the Tools and Layers sidebars wherever you want and completely customize the list of tools. Or choose one of the built-in presets created especially for photographers, designers, painters, and illustrators.

The jaw-dropping, Core ML-powered Remove Background feature removes the background from any image with just a click. Using a combination of machine-learning algorithms, Pixelmator Pro automatically selects the subject, refines the edges of the selection, then removes any traces of the previous background from the object’s edges.

To deliver more intelligent image editing, Pixelmator Pro uses machine learning — a technology that allows computers to gain knowledge to perform specific tasks more like a person than a computer. Which enabled us to create features that have never before been possible.

Make small imperfections or even entire objects disappear from your images by painting over them with the Repair Tool. No matter how complex the background, the Repair Tool can make almost any object vanish without a trace.

With a collection of pixel-accurate selection tools powered by state-of-the-art technology, Pixelmator Pro lets you pick out and edit precise parts of your images with ease. So you can apply color adjustments and effects to specific areas. Select and copy objects from one image to another. Or focus all edits on a precise area without affecting the rest of the image.

Using the powerful Type tools in Pixelmator Pro, you can easily design great-looking text in all your images. Effortlessly create curved text or type along shapes and paths. And use a full set of typography tools to customize text in any way you can imagine.

Pixelmator Pro includes a range of intuitive and easy-to-use tools for designing curved and circular text. Use the Circular Type tool to create circular text, the Path Type tool to create path text, or type text around the edges of any default or even custom shape.

Pixelmator Pro comes with a collection of over 60 versatile effects that you can mix and combine to develop any artistic or special effects you can imagine. Effects are nondestructive, so you can always edit, rearrange, or remove an effect after applying it. And you can even apply multiple effects to a single layer — seeing all your changes in real time.

The effects browser makes it incredibly easy to find just the effect you need. Browse effects, search for them by name, see instant previews, and quickly apply effects to your currently selected object.

The Pixelmator Pro editing extension makes the entire Pixelmator Pro app and all its features available right inside Photos. So you can edit using Pixelmator Pro without ever leaving Photos, keeping all your nondestructive edits saved inside your library. Your Photos app is now a full-featured, layer-based image editor.

Pixelmator Pro is designed from the ground up to be easy to use for beginners. But it’s ready to progress with you as you start mastering image editing, so you’ll also find many advanced features like Export for Web, Soft Proofing, support for Adobe Photoshop files, color management, AppleScript, and more.

From its app icon and the way it looks and feels to the technologies it supports, Pixelmator Pro has been designed to be the ultimate Mac app. Enjoy full support for every Mac feature and technology you’d expect — iCloud, Versions, Shortcuts, Sidecar, Apple Pencil, and many others.

The Pixelmator Pro image editing engine is seriously sophisticated and incredibly powerful. It’s designed exclusively to take advantage of the full power of Mac computers, using advanced Mac graphics technologies like Metal and Core Image. Pushing the boundaries of image editing, Pixelmator Pro also includes machine learning-enhanced editing features powered by Core ML. So tools aren’t just blistering fast — they’re whip smart too.

The groundbreaking machine learning features in Pixelmator Pro are integrated using Core ML, which brings the best possible ML processing performance on Mac.

Pixelmator Pro has an average worldwide rating of 4.8 stars out of 5 with over 32,000 five-star ratings. It also has a Mac App of the Year award and proudly sports an Editors’ Choice badge on the Mac App Store. We think you’ll love it — and we’re not the only ones.

Quickly change the mood of your image by making all the colors warmer or cooler, or use the machine learning-powered White Balance to automatically fix white balance in shots with unwanted color casts.

Use Lightness to perfect the lighting in your shots. Lift the shadows and pull in highlights to reveal hidden detail. Adjust Brightness to enhance photos that are a little too bright or too dark. Or increase contrast to make the colors, textures, and subjects in your shots stand out.

Use the Replace Color adjustment to replace any color in your image with any other. You can pick both the color you want to replace and its replacement in any way like. For example, using the built-in Color Picker to pick a color directly from your image, or using the native Colors window.

Featuring a range of options that help bring out the contrasts, textures, lighting, and shadows in your black-and-whites, the Black & White adjustment lets you create beautiful black and white photography, even from your color photos.

One of the problems with old CRT monitors, over time, was a condition called burn-in. This phenomenon resulted in an imprint of an image onto the display that was permanent, caused by the continuous display of a particular picture on the screen for extended periods. A breakdown in phosphors on the CRT results in the image being burned into the screen, hence the term. Is there such a thing as LCD screen burn-in?

LCD monitors use a different method for producing the image on the screen and are immune to this burn-in effect. Rather than phosphors generating light and color, an LCD uses a white light behind the screen with polarizers and crystals to filter the light to specific colors. While LCDs are not susceptible to burn-in the same way CRT monitors are, LCDs suffer from what manufacturers call image persistence.

Like the burn-in on CRTs, image persistence on LCD monitors is caused by the continuous display of static graphics on the screen for extended periods. Long-term-static images prompt the LCD crystals to develop a memory for their location to generate the colors of that graphic. When a different color appears in that location, the color will be off and will display a faint image of what was previously displayed.

The persistence is the result of how the crystals in the display work. The crystals move from a position allowing all light through to one that doesn"t allow any. It"s almost like a shutter on a window. When the screen displays an image for an extremely long time, the crystals can switch to a particular position. It may shift a bit to alter the color, but not completely, resulting in a display other than the one intended.

This problem is most common for elements of the display that do not change. Items that are likely to generate a persistent image are the taskbar, desktop icons, and background images. These tend to be static in their location and displayed on the screen for an extended period. Once other graphics load over these locations, it might be possible to see a faint outline or image of the previous graphic.

In most cases, no. The crystals have a natural state and could shift depending on the amount of current used to generate the desired color. As long as these colors change periodically, the crystals at that pixel should fluctuate enough, so the image doesn"t imprint into the crystals permanently. However, if the screen is always on the image that doesn"t change, the crystals could obtain a permanent memory.

Set the screen to turn off after a few minutes of idle time. Turning off the monitor display prevents images from appearing for extended periods. Setting the monitor to do this when the computer is idle for 15 to 30 minutes can make a difference. These values appear in the Mac Energy Saver settings or Windows Power Management.

Rotate any background images on the desktop. Background images are a common cause of image persistence. By switching backgrounds every day or every few days, you"ll reduce the risk of persistence.

Using these items can prevent the image persistence problem from cropping up on a monitor. If the monitor displays image persistence problems, here are a few steps that can be used to correct it:

Some Google Assistant devices, like speakers, Smart Displays, Smart Clocks, TVs and the Pixel Stand, can be shared with multiple people. For any shared device, you can turn on personal results to allow the Google Assistant to read or show results specific to you. For example, the Google Assistant may show:

If Voice Match is turned on, Google Assistant won"t respond with your personal results to a voice it doesn’t recognize as yours. Learn how to use Voice Match and personal results.