the smallest one) was the fastest, clocking in with an average response time of 5.33 seconds to fully load the JPG then took an average of 8.34 seconds and the 100% lossless WebP file took an average of 12.28 seconds. Unsurprisingly, the 80% lossy WebP file (i.e. I placed the three images above on standalone test pages, and put all three pages simultaneously under siege (a benchmark utility testing tool I’ll talk about more in another post), hitting my test pages with around 25 simultaneous users to see how quickly their response times would be. Don’t compress already compressed files over and over, or you will compound the quality deterioration. Pro tip: if you compress to lossy formats, you should always compress the original image. In addition, lossy images lose their quality irreversibly - you can’t go back once you’ve converted it to a lossy format, which means that if you compress the same lossy image over and over, each time, the quality deteriorates. Lossy compression (the one on the right above) creates images that are approximately the same as the original: but because of the compression, the size is smaller (and quality sometimes suffers - although in this case, it’s barely noticeable). Do not convert it to a lossy file format (like JPG or GIF) first. As a result, the final file will end up even larger than if you had converted it directly from the original PNG file! Pro tip: if your original image is a lossless file format (like PNG, BMP, or Raw), convert it straight to a WebP image. When you reverse the process and try to convert the lossy JPG back to a lossless file format (like WebP), the algorithm will strip out unnecessary metadata (good) - but it will also encode each artifact it finds to reproduce it pixel-perfect (bad), often resulting in a file size increase, but no visual benefits. During this compression process, the converter adds what is known as artifacts. This is because my original image was actually a lossless PNG file, which I then converted and ran through an image compressor to produce a smaller JPG file. So you’re probably wondering why the lossless WebP image is actually bigger than the original JPG. (Above photos too small to see the difference? If you want to see the 80% lossy WebP image live in action, head on over to my website.)
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |