upper jpeg quality, but looks worse

[tczf1128]

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]

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.

[tczf1128]

thanks