dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-13 06:24:27 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

Added image characteristic hint for the codec.

Browse Source 
This image type hint is used by codec to apply appropriate set of
transform filters to the image.

Change-Id: Ibb24e47ba14c40fa7f9f2c50ae86e03f2b29e9a6
This commit is contained in:
Vikas Arora
2012-06-22 12:14:48 +05:30
parent e8a0a821d2
commit d373076a53
5 changed files with 44 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
src/enc/config.c
View File

@ -45,6 +45,7 @@ int WebPConfigInitInternal(WebPConfig* const config,
config->alpha_filtering = 1;
config->alpha_quality = 100;
config->lossless = 0;
config->image_hint = WEBP_HINT_DEFAULT;
// TODO(skal): tune.
switch (preset) {
@ -119,6 +120,8 @@ int WebPValidateConfig(const WebPConfig* const config) {
return 0;
if (config->lossless < 0 || config->lossless > 1)
return 0;
if (config->image_hint > WEBP_HINT_PHOTO)
return 0;
return 1;
}

21
src/enc/vp8l.c
View File

@ -139,19 +139,24 @@ static int AnalyzeEntropy(const WebPPicture* const pic,
return 1;
}
static int VP8LEncAnalyze(VP8LEncoder* const enc) {
static int VP8LEncAnalyze(VP8LEncoder* const enc, WebPImageHint image_hint) {
const WebPPicture* const pic = enc->pic_;
assert(pic != NULL && pic->argb != NULL);
enc->use_palette_ =
AnalyzeAndCreatePalette(pic, enc->palette_, &enc->palette_size_);
AnalyzeAndCreatePalette(pic, enc->palette_, &enc->palette_size_);
if (!enc->use_palette_) {
double non_pred_entropy, pred_entropy;
if (!AnalyzeEntropy(pic, &non_pred_entropy, &pred_entropy)) {
return 0;
}
if (image_hint == WEBP_HINT_DEFAULT) {
double non_pred_entropy, pred_entropy;
if (!AnalyzeEntropy(pic, &non_pred_entropy, &pred_entropy)) {
return 0;
}
if (pred_entropy < 0.95 * non_pred_entropy) {
if (pred_entropy < 0.95 * non_pred_entropy) {
enc->use_predict_ = 1;
enc->use_cross_color_ = 1;
}
} else if (image_hint == WEBP_HINT_PHOTO) {
enc->use_predict_ = 1;
enc->use_cross_color_ = 1;
}
@ -945,7 +950,7 @@ WebPEncodingError VP8LEncodeStream(const WebPConfig* const config,
// ---------------------------------------------------------------------------
// Analyze image (entropy, num_palettes etc)
if (!VP8LEncAnalyze(enc)) {
if (!VP8LEncAnalyze(enc, config->image_hint)) {
err = VP8_ENC_ERROR_OUT_OF_MEMORY;
goto Error;
}

8
src/webp/encode.h
View File

@ -46,6 +46,13 @@ WEBP_EXTERN(size_t) WebPEncodeBGRA(const uint8_t* bgra,
//------------------------------------------------------------------------------
// Coding parameters
// Image characteristics hint for the underlying encoder.
typedef enum {
WEBP_HINT_DEFAULT = 0, // default preset.
WEBP_HINT_PICTURE, // digital picture, like portrait, inner shot
WEBP_HINT_PHOTO // outdoor photograph, with natural lighting
} WebPImageHint;
typedef struct {
float quality; // between 0 (smallest file) and 100 (biggest)
int target_size; // if non-zero, set the desired target size in bytes.
@ -77,6 +84,7 @@ typedef struct {
int alpha_quality; // Between 0 (smallest size) and 100 (lossless).
// Default is 100.
int lossless; // Lossless encoding (0=lossy(default), 1=lossless).
WebPImageHint image_hint; // Hint for image type.
} WebPConfig;
// Enumerate some predefined settings for WebPConfig, depending on the type