upper jpeg quality, but looks worse

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tczf1128
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upper jpeg quality, but looks worse

Post by tczf1128 » 2018-12-11T02:20:51-07:00

I have a jpeg with 50 quality, when I convert it to webp and set quality to 90, the result looks worse. its why?

Code: Select all

convert zjb_origin.jpeg -quality 90% xx.webp
it is the origin jpeg, http://smellycat.oss-cn-hangzhou.aliyun ... rigin.jpeg

snibgo
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Re: upper jpeg quality, but looks worse

Post by snibgo » 2018-12-11T03:33:11-07:00

JPEG is a lossy format. This means the compression code changes the pixel values when the file is written. Lower quality number gives better compression but causes more change.

The data is lost. You can't get it back by reading the JPEG and saving the image to another format.
snibgo's IM pages: im.snibgo.com

tczf1128
Posts: 21
Joined: 2018-12-04T22:47:49-07:00
Authentication code: 1152

Re: upper jpeg quality, but looks worse

Post by tczf1128 » 2018-12-11T03:56:34-07:00

thanks

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