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technopagan / adept-jpg-compressor

A Bash script to automate adaptive JPEG compression using common CLI tools
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Move from boolean Yes/No compression to a three-step No/Little/Heavy compression pattern #13

Open technopagan opened 11 years ago

technopagan commented 11 years ago

To further reduce bytesize, Adept needs a more granular approach to compression.

As of now, the only decisive factor if we can apply high compression to a tile is the black-white median decimal "0.825". If a tile ranks below that threshold, it gets compressed more heavily.

We can introduce a multi-threshold step system here that e.g. applies no compression, a little compression (~q=75) or high compression of the median is zero. This way, Adept may be able to save more bytes.

joeyhoer commented 10 years ago

I had the same idea while fiddling with SaliencyDetector. There may be a way to use variable compression ratios based on the output luminosity of --blocks or --qblocks option already. Or average the luminosity of the default output with imageMagic to achieve the same effect.

I agree, something more than an "on/off" compression could be desirable, and may yield better results.