Pixelization occurs when the individual pixels of a digital image become visible to the naked eye. In many cases, it results from zooming in on an image beyond the resolution of the computer monitor. The individual pixels become more conspicuous, and the image takes on a grainy or blocky appearance. This happens when we enlarge or up-sample a low-resolution image; the loss of image quality is an undesirable phenomenon.
However, we employ pixelization in censorship to make certain parts of images completely obscured, in which case the degraded image quality is intentional.
Also, a visual style uses pixelization to simulate the graphics of the early computer age, when images were boxy and had a limited color range. Pixel art is nostalgic and gaining popularity.
In this article, we’ll define pixelization, the terms describing the effect, how it is both useful and a nuisance, and how to create or avoid it.
Contents
The Difference Between Pixelation and Pixelization
Pixelation is the process of creating a digital image. A scene is captured by a camera sensor, which converts it into rows and columns of pixels. The data collected by pixels during this process are hue, saturation, and lightness (HSL). Also, we call this process rasterization.
However, pixelization is a reduction of the number of pixels, with a corresponding increase in the size of those pixels that comprise an image. By zooming in on the image on a computer screen, the result is pixelization of that image. In most cases, pixelization is not desirable. Typically, we want to display a high-quality picture or photograph. But there are exceptions.
Pixelization is a Common Method for Censoring Content
Television news and websites routinely obscure elements such as faces and sensitive information using a technique of pixelization or alternative techniques like blurring. This practice aims to hide elements that may be inappropriate or are not cleared for publication.
In television broadcast depictions or online productions, editors routinely obscure the license plate of a car or the faces of suspects or bystanders at crime scenes using pixelization. The law requires this to preserve a presumption of innocence as well as the right to privacy.
Images or video footage of nudity use pixelization or censor bars to obscure genitalia, pubic hair, or a woman’s nipples to comply with decency standards, which vary in many countries. Drug references and obscene words or gestures are also censored by pixelization or other methods. An audio beep censors obscene language, while pixelization or a black rectangular shape over the speaker’s mouth negates lip reading.
A corporate logo in a photograph, art print, or video may also be obscured using pixelization to avoid trademark violations.
How to Censor an Image Using Pixelization
Various image editing programs feature a standard graphics filter to create pixelization, including Photoshop, GIMP, and Pixir. These platforms allow you to pixelize the entire image or select a specific section.
In the photo below, I used Photoshop to obscure the girl’s entire face. After opening the image, I selected an area using the Elliptical Marquee Tool. Under Filter, I chose Pixelate, and under that, Mosaic. A window labeled Mosaic allowed me to adjust the Cell Size of the censoring pixels. The window also has an option to preview the resulting image.
With the facial features properly obscured, clicking OK saves the image.
Pixelization as an Art Form
In the art world, we find pixelization trending. Pixelized art creates the effect of zooming in and enlarging the pixels. Viewed on modern high-resolution screens, each of the image’s original pixels occupies a large number of the display’s pixels.
In pixel art, the pixels are a central part of the artistic effect of the composition of the piece. With careful control over pixel placement, for example, changing the number and size of the pixels has a dramatic effect on the overall artwork.
Employing software to generate pixel art places many pixels automatically. Pixel art generally has large pixels and a small color palate. This can lead to an aesthetically jarring effect; however, computer-rendered pixel art can produce a larger number of colors.
The Pixel Art – Video Game Connection
Pixel art is undergoing a revival of sorts. These digital illustrations recall the early days of video games when developers and designers created graphics with blocks of color assembled as a mosaic. The stair-step lines and high-contrast colors defined video game characters. But what we generally considered low resolution images have taken on a new identity as an artistic genre.
The artists and developers of early video games worked hard to hide the technical limitations they faced. In the late 1980s and early ’90s, that meant trying to make graphics look smooth on a 320×256 pixel screen.
The constraints of the technology shaped their graphic style, which the art community accepts as a calculated art style.
Two primary categories of pixel art are isometric and non-isometric. Isometric pixel art creates a 3-D appearance, while non-isometric pixel art shows just one side, usually the top or front. However, IMAI Shin, the vice editor-in-chief of IGN Japan, identified upwards of 20 pixel art styles.
How to Avoid Pixelization?
One way to avoid pixelization is to create vector images. Instead of being constructed of pixels, or raster based images, vector images use mathematical commands that place lines and shapes in space. This allows for scaling, or enlarging the images, and pixelization does not occur.
With a raster image, such as a JPEG or TIFF, each pixel contains information that must be stored. This makes for large files, especially in RAW format. Vector images consist of a series of points to be connected by lines and shapes and are smaller than raster files.
The advantages of vector images are scalability, small file size, and precision. The disadvantages include less detail, limited browser support, and inconsistency among applications.
AI Upscaling without Pixelization
Enlarging a JPEG image involves making each pixel larger. As the size of an image increases, the pixelization also increases, resulting in a blocky look. Upscaling with artificial intelligence occurs with increased context awareness.
This process introduces new pixels of image information, adding detail and filling in gaps to create a larger image with higher resolution. The machine learning model recognizes patterns and adds pixels with great accuracy.
A number of AI upscaling applications are available. Adobe Lightroom features a tool called Super Resolution that quadruples image size with refined color and greater detail. I was skeptical about this feature, but I’ve found that it adds detail and clarity along with the increase in image size.
Gigapixel AI from Topaz Labs uses advanced neural networks to enlarge photos up to 600 percent. It can integrate with programs such as Photoshop and Lightroom.
Upscale.media is an online tool and mobile app that can enhance a variety of file formats. This platform upscales images up to 4 times, maintains detail, and erases artifacts.
Summary
Pixelation is the conversion of a subject into pixels. This happens in a camera. When a sensor plate captures an image projected from the lens, the sensor creates a raster file. Most of what we work with on a computer is already pixelated.
Pixelization is the deliberate reduction of the number of pixels, which increases pixel size. This proves useful for censorship or artistic purposes. When we reduce the resolution of a pixelated image, we increase the size of individual pixels, giving the image a distinctly blocky appearance. That is pixelizing.
While this creates a low-resolution image that is usually not the goal, it is very useful for completely obscuring parts of an image or an entire image. In addition, artists and designers use large pixels in creating pixel art, a nostalgic style that evokes the early video game graphics.
I hope this article brings clarity to a subject that may not be top-of-mind, but is important in photography. If you have any questions or comments, please submit them in the space below.
Take Away
- Zooming in on a digital image increases the pixel size and reduces the number of pixels, a process known as pixelization. This method proves useful to media outlets for censorship purposes. An artistic movement, pixel art, adopted this technique to create images that recall the early days of video games.
Daniel wrote a interesting article on Pixelation and it brought back memories when video games came out in the mid 70’s and characters were all pixels. Back then we all took it as cheap video games. One thing that really stood out was pixelation is creating a resurgent of creating art with this process.
Thank you.