Short Guide to Image Formats
If you are just venturing into the design universe, one of the first challenges you are likely to encounter is when you should use one image format or another, i.e., should you use a PNG or a JPEG? Is it even necessary to know these image formats or when to use them? Yes, it is. You see, when you know the difference and understand the variations between each of these image file formats, you will be able to make smart decisions to maximize your visual presentations. This is why you must make use of the right, crisp-looking images at the right places. This will help you to avoid those annoying blurs or distorted looks.
Image formats are the standard data structures that influence how a computer processes, displays, and also stores digital images. Image files may store data in one of these three image formats: compressed, uncompressed, or vector formats. Image file types store information on computers to allow for display editing, or reading by one particular program. You can check the file type by taking a quick look at the last three letters of the file name. This is the file extension, and different computer programs use different extensions to save files.
The Difference Between Raster and Vector
It is also expedient to know the significant difference between raster and vector. Raster images or photos are created by a set of single blocks – pixels – to generate images. The most popular image formats – which are raster images – include JPEGS, PNGs, and GIFs. Every image or picture you come across on the web falls under one of these three categories. Now, pixels feature a defined proportion that is determined by their quality, i.e., low-res or high-res. When you expand them, they distort, resulting in an unclear or fuzzy image. This goes to show that it is practically impossible to resize raster images without compromising their resolution. And this is why it is usually – and profoundly – recommended that you store or save raster images in the exact sizes meant for the application of the image.
Vector images, on the other hand, are far more flexible because proportionate formulas are employed instead of pixels. Images that require repeated resizing fall under format files such as PDF, AI, and EPS. Brand and logo images are, in many instances, created as vectors. The most impressive thing about vectors is that you can resize them to be as huge as a billboard ad or as small as a postage stamp without compromising the quality of the image.
Popular Image Formats
There are thousands of image formats that are utilized to display or save pictures. But the following are considered the “heavyweights” in the creative industry these days since they are the most widely-used image formats. So, here they are in no particular order:
JPEG – also referred to as JPG – stands for Joint Photographic Experts Group, the technical team behind its development. This image format was created in 1994 and has since become the standard graphic file format. It is undisputedly the most popular or well-known image format on the web. JPEG files are somewhat lossy, which means that lots of information are lost from the original photo as soon as it becomes a JPEG file. This image file format disposes of the majority of the information to be able to save and convert the image into a small file. So, to some extent, the quality of the original image will be diminished. Almost all digital cameras make use of the JPEG format. Users of these cameras can take high-resolution pictures – that are packed with many colors – and save each one of them as JPG files. This file format depends on a sophisticated compression algorithm that lets users produce graphics – that are smaller sized – via the reduction of the quality of the image. And since the file is smaller, JPEG is super web-friendly. They do not take up a lot of room, and the transfer time is incredibly minimal. JPEG files are also known to be less grainy than GIFs.
- Extremely web-friendly
- Small file size
- Excellent for use for images and photos packed with lots of vibrant and rich colors, thanks to its 16 million different color combinations and colors
- Images saved in this format are crystal-clear
- Almost every digital camera out there uses the JPEG format
- Widespread support
- Suitable for most uses; widely accepted and recognized image format
- Not ideal for photographs with sizable blocks of shades
- Not suited for images with text
- When the image is compacted, the color and text become fuzzy
- No support for transparency
- Repeated editing or opening and saving the same image may influence the quality
- Cannot be animated
- Develops artifacts after a compression
TIFF – an acronym that stands for “Tagged Image File Format” – is an image file format that is often preferred by creative professionals such as photo experts and graphic designers. This format provides support for transparency, layers as well as other technical conformities that most users appreciate. Aldus developed it for desktop publishing; however, by 2009, its key control was shifted over to the Adobe system. TIFF does not compress by default, and this is why they are usually large, thereby taking up a lot of storage space. You can compress them using various non-lossy compression schemes. Still, with Photoshop, you can only apply non-lossy LZW compression, a format that is suitable for direct publishing on the web. TIFF is perhaps the least popular image format, and that is because it is hardly acknowledged as a file format by websites. And even though several types of TIFF files exist, no single reader can read and scan them all, thereby resulting in different format issues down the line. However, the printing world, the TIFF file format is considered as one of the best choices with its organic result.
- Saves formats with layers
- Incredibly flexible
- Produces vibrant-colored, high-quality images along with all the information retained
- Supports a wide range of compression formats, including even zero compression
- Suitable for use in terms of printing
- Not ideal for web publishing
- Files are too large and take up too much storage space
- Demands extended transfer time
Once upon a time, animated GIFs were the rage a few short years ago. However, this widely used web image format appears to have undergone a resurgence lately with the emergence of video playback on the web. A video can readily be converted into an animated GIF that is natively supported by various browsers out there without the need for a plugin. GIF – which stands for Graphics Interchange Format – reduces the number of colors – up to hundreds of thousands – in an image to 256. This file format supports transparency, unlike JPEG, and also possesses the singular ability to display a series of images, just like videos. The latter is what is referred to as an animated GIF. Interlaced GIFs can also load in portions on sites, and are typically bigger than regular GIFs. This interlacing characteristic gives the impression or appearance of fast-loading visuals. When you load GIFs onto a browser, the first one that appears will look unclear and quite blurry. But as the data is continually downloaded, the image becomes more defined and clearer.
- Performs moderate animations without the need for plugins
- Supports transparency
- Widely supported
- Can be compressed
- Suitable for creating web graphics and icons
- Extremely limited to a 256-color palette
- Considered in some quarters as an outdated file format when compared to the others on this list.
PSD is a patented or trademarked layered image format that is an acronym for “Photoshop Document.” They are authentic design files created in Adobe Photoshop and are fully editable with image adjustments and multiple layers. PSDs are majorly used in creating and editing raster images, though it can also contain vector layers as well, thereby making it unique and flexible for several projects. PSD files can be exported into any of the image formats on this list.
- Suitable for retouching photos
- Perfect for editing artwork
- Suited for use in creating digital images or photos for the web
- Layers make it possible for users to move UI elements all around
- Can be used for making fancy videos or animations
- Not suitable for printing
- Users need to convert this file format to a web-friendly format like JPG before images can be seen
PNG – i.e., Portable Network Graphics – is an image format compression that a lot of creative professionals believe will replace the GIF format. This image file format is patent-free as an Internet panel created it. It also offers better features along with several upgrades when compared to GIFs. Images saved using the PNG format will never lose their quality or details, no matter how much you compress or resize them. But it performs remarkably well when used for small images such as logos, etc.
- Widely supported, with nearly all major browsers providing full support for its numerous features
- Precisely reproduces source images
- Supports more colors than its counterpart, GIF
- Compresses easily without loss of quality
- Can save images with acute transparency
- Limited to RGB color space
- Files are far larger than regular JPGs
- Not ideal for print
Although it would have been practical to have one file format that caters to all graphic or web design needs, it is expedient that you know or identify the differences between some of the best image file formats out there and their respective uses. Hope this overview will help you to explain the different image formats so that you can know exactly which one to go for in your next design project.
Article Posted 7 Dec, 2019