alternative WebP lossless compression

last modified on 9 July 2019, by Cédric Louvrier

pingo could do some lossless image transformations for web to decrease the filesize. this is done from conversion to PNG to WebP or directly on WebP, without any loss regarding how the image is rendered once fully decoded

N: from 0 to 9 — 0: fast and good compression — 9: slow, but better compression
pingo -webp-lossless -sN target
original file: apple.png (198.27 KB) — brute-force WebP lossless encoding
cwebp -mt -lossless -m 6 -q 100 pingo -webp-lossless -s9
apple WebP lossless - cwebp apple WebP lossless - pingo
145.35 KB (2.159s) 145.35 KB (1.116s)

pingo could offer alternative lossless compression regarding the speed/size trade-off. it could be faster while offering same, better or worse savings for some RGBA samples with complex structure like the sample above

fast encoding

the fast encoding lossless mode for WebP in pingo could determine better settings in some cases. it could do that in a way that does not require brute-force trials

original file: cake.png (64.33 KB) — fast lossless WebP encoding
cwebp -mt -lossless cwebp -mt -lossless -m 5 -q 100 pingo -webp-lossless -s1
cake WebP lossless - cwebp cake WebP lossless - cwebp cake WebP lossless - cwebp
71.63 KB (0.499s) 70.18 KB (1.497s) 37.73 KB (0.198s)

PNG to WebP

pingo could do alternative trials to find out better settings

original file: box.png (30.40 KB) — paletted WebP encoding
cwebp -mt -lossless -m 6 -q 100 pingo -webp-lossless -s1 pingo -webp-lossless -s9
brown box - cwebp brute force brown box - pingo webp -s1 brown box - pingo webp -s9
18.50 KB (0.638s) 16.55 KB (0.07s) 15.46 KB (0.09s)
original file: zephyr.png (866.12 KB) — paletted WebP encoding
cwebp -mt -lossless -m 6 -q 100 pingo -webp-lossless -s1 pingo -webp-lossless -s4
zephyr - cwebp brute force zephyr - pingo webp s1 zephyr - pingo webp s4
788.06 KB (14.417s) 697.76 KB (1.231s) 672.82 KB (2.989s)

WebP optimization

pingo could try more transformation that could be more efficient than brute-force

original file: books.webp (74.08 KB) — paletted WebP encoding
cwebp -mt -lossless -m 6 -q 100 pingo -s1
zephyr - cwebp brute force zephyr - pingo webp s1
72.28 KB (1.05s) 66.21 KB (0.21s)