Let us begin by understanding(briefly for now, more on this in later blogs) what is ImageMagick ?
ImageMagick is a free and open-source tool for converting/compressing raster images.
What is WebP and why are we using this image format in the example below ?
WebP is a raster image format developed by Google, WebP is based on technology developed by On2 technologies which was later acquired by Google. WebPs lossy compression is based on VP8 video codec - Think of it as a key frame extracted from VP8(will write more about this in a later blog).
Why convert to WebP ?
WebP (widely supported across most types of devices) is a next-gen Image Format which in most scenarios gives better byte reduction at similar quality levels that a traditional image format like png/jpeg would provide. WebP lossless images are 26% smaller in size compared to PNGs. WebP lossy images are 25-34% smaller than comparable JPEG images at equivalent SSIM quality index.
Please find below a few commands i have run on my computer to convert a JPEG image to WebP at different lossy quality levels - 5, 25, 50 and 75. You can try these options to test the image at different quality levels using this(WebP) newer generation image format before deciding on the acceptable quality level.
magick autumn.jpg -quality 5 -define webp:lossless=false autumn5.webp 
magick autumn.jpg -quality 25 -define webp:lossless=false autumn25.webp 
magick autumn.jpg -quality 50 -define webp:lossless=false autumn50.webp
magick autumn.jpg -quality 75 -define webp:lossless=false autumn75.webp
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