when I Convert webp, color is gone??

[GoogleCodeExporter]

What steps will reproduce the problem?
1. color is reduce (red color)
2.

What is the expected output? What do you see instead?

What version of the product are you using? On what operating system?
windows 8.1 64bit or anyOS
Convert program : XNconvert(http://www.xnview.com/en/xnconvert/) , 
honeyview(http://www.bandisoft.co.kr/honeyview/)

bpg format is better color than webp format

Original issue reported on code.google.com by x86andro...@gmail.com on 25 Dec 2014 at 5:21

Attachments:

• [jpg 100 .jpg](https://storage.googleapis.com/google-code-attachments/webp/issue-235/comment-0/jpg 100 .jpg)
• source.png
• [webp hoenyview.webp](https://storage.googleapis.com/google-code-attachments/webp/issue-235/comment-0/webp hoenyview.webp)
• [webp lossless.webp](https://storage.googleapis.com/google-code-attachments/webp/issue-235/comment-0/webp lossless.webp)
• [bpg Hoenyview.bpg](https://storage.googleapis.com/google-code-attachments/webp/issue-235/comment-0/bpg Hoenyview.bpg)

[GoogleCodeExporter]

The change in red color is due to YUV420 subsampling.

One way to mitigate this effect is to use the '-pre 4' option in cwebp.

For instance: 

     cwebp -pre 4 source.png -o webp_pre4.webp

Attached is the resulting WebP file (75kB)

Original comment by pascal.m...@gmail.com on 26 Dec 2014 at 4:57

• Changed state: Done

Attachments:

• webp_pre4.webp