Web Designing and Image Formats
Images would form an integral part of any web-design. And knowing the image formats would help you. Many people save pictures in Windows’ default BMP (bitmap) format, but the files it creates are simply much too large to put on a website – they’d take about a minute for visitors to download and use up all your bandwidth in the process. So what are the other options or image format types available?
Remember, when you upload pictures on the web, you must consider the trade-off between image quality and speed: the smaller the file, the faster its going to upload but it might not look that great.
GIF stands for Graphics Interchange Format, and was the first image format used on the web. It was invented by CompuServe in 1987, updated in 1989. IF has certain limitations-Images stored in GIF format can only use a maximum of 256 colors, which makes things like photographs and logos look unattractive.
- GIF’s are popular mainly because it is the first image format to be used and produces very small files (in KBs). Also note that this is the only image format that allows you to create small animations.
JPEG was designed by the Joint Photographic Experts Group, which gives it the name. It was designed as a format suitable for storing high-quality photographs at low file sizes – file sizes small enough to put on the web.
Today, the format is supported in almost all web browsers. The most important feature of JPEG is the lossy compression. The word ‘lossy’ means that data is lost from the picture when it is saved at smaller file sizes.
- Image-editing softwares would allow you to choose how much compression you want, from none (highest quality, large file size) to 100% (very small files, poor quality). If you do use JPEG for your website, then I would recommended that you turn compression off altogether, or use a maximum of about 25%.
PNG stands for Portable Network Graphics, and is the latest web image format in widespread use. It was designed as a replacement for the outdated GIF format, allowing files to use millions of colours instead of only 256.
- PNG files have smaller file sizes than GIFs, although they are often larger than JPEGs, since PNG compression is lossless (never loses any image quality).
So Which Format do I Use?
I would suggest that you use either JPEG format (for photos) or PNG format (for less complicated graphics). A good image editor should be able to convert from any format to the other easily.
- In Paint Shop Pro, for example, you simply open your images and save them again using whatever format you want – you can even run the ‘Batch Converter’, which will convert a whole folder full of files all at once. If you don’t have an image editing program, there are plenty of free image converters that will convert the image formats for you.