What other image formats are there, besides JPG, BMP, and GIF? What are the strengths and weaknesses of each? Which ones are replacing web images of the future.
In this article, I’ll talk about PNG and WEBP, two image formats which are gaining as much popularity as JPG and GIF.
PNG (Portable Network Graphics) format has been developed as an open source replacement for GIF. This new format is using LZW compression. PNG very quickly gained in popularity as a wonderful file-type for Internet graphics, mainly because it supports transparency. As many know, GIF and transparency doesn’t go very well together. Transparency in this context means, that the transparent background of a PNG file blends with the background of the website. This functionality of PNG format is mainly what made it hugely popular, however, as much praised, it was initially misunderstood by novices and brought also some critique to this format. Additionally, some functionalities of PNG can also replace a common TIFF format, because PNG supports not only indexed colors, but same as TIFF, also grayscale and true-color channels.
WebP is a brand new image format developed by Google which is used mainly on the Internet in order to deliver graphics to end users of web browsers. Advantage of this format is, that the information image contains is not lost during the compression. Generally, WebP lossless (meaning uncompressed) images are about 26% smaller than for example PNG format. This incredible compression option which doesn’t compromise quality, is what situates the WebP format to be a dominant player in the future of web graphics. Similarly to JPG or GIF, WebP also supports a lossy compression. If the image has been compressed to WebP lossy format, one can expect approximately 25-34% reduction in size compared to JPEG images.
WebP, similarly to PNG also supports lossless transparency and it achieves it with only 22% additional bytes. Huge advantage of this new format is also its use of transparency in lossy compression, when one can expect approximately 3 times smaller image file sizes compared to PNG.