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Start to use libvips 8.1.0+ features #152

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Use native (un)premultiply

Support normalise on Windows
This commit is contained in:
Lovell Fuller
2015-11-12 22:14:53 +00:00
parent 58d9e0fef7
commit 20f468991f
6 changed files with 23 additions and 152 deletions
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68
src/operations.cc
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@@ -121,73 +121,10 @@ namespace sharp {
return vips_bandjoin2(outRGBPremultiplied, outAlpha, out, NULL);
}
/*
* Premultiply alpha channel of `image`.
*/
int Premultiply(VipsObject *context, VipsImage *image, VipsImage **out) {
#if (VIPS_MAJOR_VERSION >= 9 || (VIPS_MAJOR_VERSION >= 8 && VIPS_MINOR_VERSION >= 1))
return vips_premultiply(image, out, NULL);
#else
VipsImage *imageRGB;
if (vips_extract_band(image, &imageRGB, 0, "n", image->Bands - 1, NULL))
return -1;
vips_object_local(context, imageRGB);
VipsImage *imageAlpha;
if (vips_extract_band(image, &imageAlpha, image->Bands - 1, "n", 1, NULL))
return -1;
vips_object_local(context, imageAlpha);
VipsImage *imageAlphaNormalized;
if (vips_linear1(imageAlpha, &imageAlphaNormalized, 1.0 / 255.0, 0.0, NULL))
return -1;
vips_object_local(context, imageAlphaNormalized);
VipsImage *imageRGBPremultiplied;
if (vips_multiply(imageRGB, imageAlphaNormalized, &imageRGBPremultiplied, NULL))
return -1;
vips_object_local(context, imageRGBPremultiplied);
return vips_bandjoin2(imageRGBPremultiplied, imageAlpha, out, NULL);
#endif
}
/*
* Unpremultiply alpha channel of `image`.
*/
int Unpremultiply(VipsObject *context, VipsImage *image, VipsImage **out) {
#if (VIPS_MAJOR_VERSION >= 9 || (VIPS_MAJOR_VERSION >= 8 && VIPS_MINOR_VERSION >= 1))
return vips_unpremultiply(image, out, NULL);
#else
VipsImage *imageRGBPremultipliedTransformed;
if (vips_extract_band(image, &imageRGBPremultipliedTransformed, 0, "n", image->Bands - 1, NULL))
return -1;
vips_object_local(context, imageRGBPremultipliedTransformed);
VipsImage *imageAlphaTransformed;
if (vips_extract_band(image, &imageAlphaTransformed, image->Bands - 1, "n", 1, NULL))
return -1;
vips_object_local(context, imageAlphaTransformed);
VipsImage *imageAlphaNormalizedTransformed;
if (vips_linear1(imageAlphaTransformed, &imageAlphaNormalizedTransformed, 1.0 / 255.0, 0.0, NULL))
return -1;
vips_object_local(context, imageAlphaNormalizedTransformed);
VipsImage *imageRGBUnpremultipliedTransformed;
if (vips_divide(imageRGBPremultipliedTransformed, imageAlphaNormalizedTransformed, &imageRGBUnpremultipliedTransformed, NULL))
return -1;
vips_object_local(context, imageRGBUnpremultipliedTransformed);
return vips_bandjoin2(imageRGBUnpremultipliedTransformed, imageAlphaTransformed, out, NULL);
#endif
}
/*
* Stretch luminance to cover full dynamic range.
*/
int Normalize(VipsObject *context, VipsImage *image, VipsImage **out) {
#ifndef _WIN32
// Get original colourspace
VipsInterpretation typeBeforeNormalize = image->Type;
if (typeBeforeNormalize == VIPS_INTERPRETATION_RGB) {
@@ -262,11 +199,6 @@ namespace sharp {
// Cannot normalise zero-range image
*out = image;
}
#else
// The normalize operation is currently unsupported on Windows
// See https://github.com/lovell/sharp/issues/152
*out = image;
#endif
return 0;
}