Optimizing Image Compression

Here you will find some hints on how to achieve the best compression ratio with WebGraphics Optimizer for your internet graphics files:

There are 3 graphic file formats mainly used for internet images: GIF (standard, interlaced, transparent, animated), JPEG, and the new PNG. Most internet browsers currently support only GIF and JPG images, so we don’t recommend using the PNG graphics file format at this time. Be careful with progressive JPG too, because there are also some browsers that don’t support this file format.

What is the best internet graphics file format for a given image?

That depends on what the characteristics are of that specific file: The LZW compression algorithm used by GIF files is best for images with less colors and wide plain areas with one color. It’s a lossless format, that means you can change and save GIF files without loosing some image information every time you’re saving. The greatest advantage of GIF is that you can choose a transparent color and create animated sequences. If you want to use these features you can only choose GIF as your internet graphics file format.

GIF files support up to 256 colors, so it’s not the best choice for photo realistic images. For that kind of images you should use JPEG file format. It produces much smaller images and always saves an image in 24 bit (for color images) or 8 bit (for grayscale images). With JPEG, there are some less or more obvious flickers and hisses visible, depending on the compression ratio you’ve selected. WebGraphics Optimizer assists you perfect in choosing the best compromise in image quality and file size.

If you are not sure which graphics file format to choose, GIF or JPEG, then we suggest you to open two variations, one with GIF and one with JPEG. Then you can play with the color and compression settings to find out which format to choose.