dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-14 21:09:55 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

add LSIM metric to WebPPictureDistortion()

Browse Source 
LSIM stands for "local similarity": before matching
a compressed pixel to the source, we search around in the source
and minimise the squared error. So, this is close to PSNR calculation,
but mitigates some of its limitations (pure translation and noise for instance).

There's a new -print_lsim option to cwebp too.

Change-Id: Ia38561034c7a90e71d2ea0f55bb1de527eda245b
This commit is contained in:
Pascal Massimino
2012-10-18 08:26:40 -07:00
parent c3aa215afa
commit f86e6abe1f
5 changed files with 129 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
src/webp/encode.h
View File

@ -359,13 +359,13 @@ WEBP_EXTERN(void) WebPPictureFree(WebPPicture* picture);
// Returns false in case of memory allocation error.
WEBP_EXTERN(int) WebPPictureCopy(const WebPPicture* src, WebPPicture* dst);
// Compute PSNR or SSIM distortion between two pictures.
// Compute PSNR, SSIM or LSIM distortion metric between two pictures.
// Result is in dB, stores in result[] in the Y/U/V/Alpha/All order.
// Returns false in case of error (pic1 and pic2 don't have same dimension, ...)
// Returns false in case of error (src and ref don't have same dimension, ...)
// Warning: this function is rather CPU-intensive.
WEBP_EXTERN(int) WebPPictureDistortion(
const WebPPicture* pic1, const WebPPicture* pic2,
int metric_type, // 0 = PSNR, 1 = SSIM
const WebPPicture* src, const WebPPicture* ref,
int metric_type, // 0 = PSNR, 1 = SSIM, 2 = LSIM
float result[5]);
// self-crops a picture to the rectangle defined by top/left/width/height.