In the early days, computers were able to display only lines of text. With the constant improvement of graphic resources, both hardware and software, different shapes and colors became part of the routine of those who use these machines, a situation that, little by little, resulted in the appearance of different image formats. Many of these became popular with the internet. This is the case of the JPEG, GIF and PNG standards, the main features of which we present below.
In addition, the text will also briefly show other known, but less used formats: Bitmap, TIFF, RAW, SVG and WebP. Finally, it will explain what Exif is.
JPEG format (JPG)
The JPEG format, which stands for Joint Photographic Experts Group on Abbreviationfinder, had its first specification made available in 1983 by a group of the same name. It is one of the most popular standards on the internet for combining two important characteristics: it offers reasonable levels of image quality and generates small file sizes when compared to other formats, facilitating its storage and distribution.
JPEG makes this possible because it is a format that uses image compression. But what is this? In a nutshell, compression consists of eliminating redundant data in files. In the case of images, it is possible to do compression in such a way that the removal of information does not impair quality (lossless), just as it is possible to use higher levels of compression that cause visible losses (lossy).
The latter is what happens in JPEG: in this format, the higher the level of compression, the smaller the file size, but the worse the image quality. The level of compression can be determined in imaging programs. Each time the same JPEG image is saved, quality is usually lost, since, generally, the software used to treat it applies compression, even if minimal, every time this action is performed.
JPEG is capable of working with almost 16.8 million colors (24 bits). This feature, combined with the compression capacity that reduces the size of the files, makes the format an excellent option for the distribution of photographic images, so much so that the format is widely used for the generation of photos in digital cameras. This is because, even if there is a loss of quality, it occurs in a little or not perceptive way, as long as, of course, there is no “abuse” of the use of compression or frequent rescues. In the case of professional activities, the use of formats that preserve quality is recommended.
JPEG files are generally used with the extensions.jpg (most frequently) and .jpeg, and there may be others according to the algorithms used. Learn more at www.jpeg.org.
Other image formats
JPEG, PNG and GIF formats are the most used, mainly on the internet, but obviously, they are not the only ones. Below you can find a brief description of some known, but less used, patterns.
Bitmap format
The Bitmap is one of the oldest and also one of the simplest image formats. Widely used in Microsoft Windows operating systems, images in this format can support millions of colors and preserve details.
However, files in this pattern are usually very large, since they do not use compression. This process is even possible on images with 256 colors or less, but it is not common.
Bitmap files can have a.dib (Device Independent Bitmap) or BMP (Microsoft Windows standard) extension and do not support a “transparent background”.
TIFF format
Acronym for Tagged Image File Format, TIFF consists of a format widely used in professional applications, such as images for medical or industrial purposes. Created in 1986 by Aldus, a company later acquired by Adobe, it is also widely used in digitization activities, such as scanner and fax, which, in fact, motivated its development.
The TIFF format offers a lot of colors and excellent image quality, which considerably increases the size of your files, although it is possible to mitigate this aspect with compression without loss of information.
An interesting detail is that the TIFF format supports the use of layers, that is, you can use different versions of the image to be worked on in a single file.
TIFF images usually use a.tif or.tiff extension and support “transparent background”.
RAW format
The RAW format (translating, something like “raw”) is a little different from the others. It is a pattern that stores all the data in a photo, just as it was generated on the digital camera, without applying effects or adjustments. Because of this, it offers high image quality and greater color depth. It is clear that when a RAW photo is compressed there may be a loss of quality, even if slight. Despite this, this option is often considered, since images in this pattern tend to result in really large files.
Most cameras allow the user to choose the format of the photographs, with RAW being an option. And why choose it? As the files in this standard are “pure”, the editor is free to use the image as it was captured and apply its own effects or adjustments. The end result can be a beautiful photo, even when it is later converted to a more “usable” format, such as JPEG or PNG. This makes RAW nicknamed the “digital camera negative”, although it is not necessarily that.
RAW format files support several extensions. That’s because each digital camera manufacturer works to its own specifications.
SVG format
SVG stands for Scalable Vector Graphics and, as the name implies, it consists of a pattern that works with vector images. It is also an open format, developed by W3C and which officially appeared in 2001. Instead of being based on pixels, that is, the “dots” that form the images, as in the patterns shown previously, the SVG uses the XML language to describe what the file should look like.
Thanks to this, SVG is able to work well with both static figures and animated images. In addition, as a vector pattern, images in the format can be enlarged or reduced without causing loss of quality.
Files in this format have a.svg or.svgz extension and support transparency effects. Learn more at www.w3.org/Graphics/SVG.