In the world of design, specifically when using a computer to do the design, you will come across different file types for images you may be using. There are a variety of different file formats, but is one better than that of another to use in your design? This article will explain the differences between each of the file formats and give you a little more background into the computer image world.
What is an Image File Format?
An image file format is a way to store and organize digital images. The original image is rasterized (ala dot matrix) into different formats for computer use. Basically, the rasterized image is a grid of pixels, which each has a different color depth. The image files are then formatted or compressed into different file sizes. The two image file compression algorithms are lossless and lossy. Lossless is used to preserve a perfect copy of the original image, but may be a larger file. Lossy keeps some of the original image, but trades image quality for file size.
Amount of Color
Images have a variety of different colors in them. Image file formats then will use a certain amount of fixed colors. The highest display would show16 million colors (or even more) without restriction. The eye doesn’t distinguish certain similar colors, so the 16 million colors or 24 bit is known as TrueColor.
Image File Formats
JPEG/JFIF/JPG – Developed by the Joint Photographic Experts Group to be a standard image file for photographers. JPGs are the most common image found on the internet and in digital cameras, mostly because they can be greatly compressed. Quality is a factor with JPGs as even the highest setting still has the file in a lossy compressed format. JPGs do no support transparency, which allows the background to be seen through the image.
GIF – Another image file closely associated with the internet is the “Graphics Interchange Format” or GIF file. GIFs are not lossy, but are limited to the 256 color palette as they are an 8-bit color file. GIF also supports animation, but still has the limitation of colors. The GIF format is still being used, but most have moved on to PNG for a better color dynamic.
PNG – Portable Network Graphics was created as an alternative to GIF. PNG supports 8-bit color as well as 24-bit color RGB like a JPEG and is the most used lossless image compression format on the internet. PNG also supports variable transparency, which means that you can change the level of how transparent you want your image to be.
TIFF – The Tagged Image File Format is usually used a completely lossless image storage format, which result in a huge file size.
What to Use
If you are creating or using an image that does not contain photographic elements, you will want to use something that can be transparent: PNG or GIF. If you are not using a lot of colors, then the GIF format should be used. It is best to use the JPG, PNG and TIFF formats when dealing with photographs. Remember that PNG and TIFF will result in larger files, so size also comes into play when creating graphic based files.
Your final decision should be based on the overall quality that you need your image to be. There are plenty of options when creating your design.