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webp and jpg - parameters for high-quality photos

Posted: 2019-06-18T03:09:55-07:00
by caho
Hello!

for jpg I use:
convert ^
-quality 90 ^
-filter Lanczos ^
-sampling-factor 4:4:0 ^
-define jpeg:dct-method=float ^

for webp I use:
convert ^
-quality 60 ^
-define webp:lossless=false ^

Tell me, what parameters should I use for jpg and webp? can i miss something? I need better quality for the photo

Re: webp and jpg - parameters for high-quality photos

Posted: 2019-06-18T05:45:45-07:00
by snibgo
caho wrote:I need better quality for the photo
What is wrong with the quality? Why not use "-quality 100"?

JPG is 8 bits/channel/pixel, and is lossy (it changes pixel values). For best quality, don't use JPG.

I don't use WEBP and can't advise on it.

Re: webp and jpg - parameters for high-quality photos

Posted: 2019-06-18T12:19:16-07:00
by caho
snibgo wrote:
2019-06-18T05:45:45-07:00
for best quality, don't use JPG.
I need to use jpg and webp. need to.
I can set the quality to 100. But there are other parameters. I do not know what to exhibit there.
filter Lanczos? or is there a better option?
sampling-factor 4:4:0? or is there a better option?

and webp?

Re: webp and jpg - parameters for high-quality photos

Posted: 2019-06-18T12:40:32-07:00
by fmw42
You have not given full command lines for your processing. -filter lanczos does nothing unless you are resizing the image. Sorry, I am not an expert on jpg or webp arguments. And results may depend upon the input image. Perhaps you should try experimenting to see what gives you the best results.