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| author | Tomaz Vajngerl <quikee@gmail.com> | 2012-06-02 20:16:36 +0200 |
|---|---|---|
| committer | Jan Holesovsky <kendy@suse.cz> | 2012-06-04 16:12:43 +0200 |
| commit | 47e0df5cebc05576e55210c5dd408a6f3eb91700 (patch) | |
| tree | 4c0db048267ba6064b1cea4915e81f6b381927e3 /vcl/inc | |
| parent | fdo#50628 fix resource file name (diff) | |
| download | core-47e0df5cebc05576e55210c5dd408a6f3eb91700.tar.gz core-47e0df5cebc05576e55210c5dd408a6f3eb91700.zip | |
fdo#46378: Lanczos3 resampling of images added to Bitmap.
Current resampling methods for images are FAST and INTERPOLATE.
FAST is used where speed of resampling is required, on the other
hand INTERPOLATE resampling is used when we need quality. For
example INTERPOLATE resampling method is used at PDF export.
INTERPOLATE resampling uses bilinear interpolation which is known
to be lower quality as other modern (and slower) resampling
algorithms such as Lanczos, Mitchell or BiCubic resampling.
This change adds Lanczos resampling to the Bitmap class and
enables Lanczos resampling in PDF export.
Lanczos3 resampling is implmented using separable convolution
with which it is also possible to easily add other resampling
methods like BiCubic just by changing the kernel function.
Change-Id: I8dff5b65753b09dffd5bc34f2343d9818efb3e58
Diffstat (limited to 'vcl/inc')
| -rw-r--r-- | vcl/inc/vcl/bitmap.hxx | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/vcl/inc/vcl/bitmap.hxx b/vcl/inc/vcl/bitmap.hxx index 17041d809e74..14aae27f1b62 100644 --- a/vcl/inc/vcl/bitmap.hxx +++ b/vcl/inc/vcl/bitmap.hxx @@ -49,6 +49,7 @@ #define BMP_SCALE_NONE 0x00000000UL #define BMP_SCALE_FAST 0x00000001UL #define BMP_SCALE_INTERPOLATE 0x00000002UL +#define BMP_SCALE_LANCZOS 0x00000003UL // ----------------------------------------------------------------------------- @@ -276,6 +277,18 @@ public: SAL_DLLPRIVATE sal_Bool ImplScaleFast( const double& rScaleX, const double& rScaleY ); SAL_DLLPRIVATE sal_Bool ImplScaleInterpolate( const double& rScaleX, const double& rScaleY ); + SAL_DLLPRIVATE bool ImplScaleLanczos( const double& rScaleX, const double& rScaleY ); + + SAL_DLLPRIVATE void ImplCalculateContributions( const int aSourceSize, const int aDestinationSize, + const double aSupport, const int aNumberOfContributions, + double* pWeights, int* pPixels, int* pCount ); + SAL_DLLPRIVATE bool ImplHorizontalConvolution( Bitmap& aNewBitmap, BitmapReadAccess* pReadAcc, + int aNumberOfContributions, double* pWeights, int* pPixels, int* pCount ); + SAL_DLLPRIVATE bool ImplVerticalConvolution( Bitmap& aNewBitmap, BitmapReadAccess* pReadAcc, + int aNumberOfContributions, double* pWeights, int* pPixels, int* pCount ); + + SAL_DLLPRIVATE static double ImplLanczosKernel( const double aValue, const double aSupport ); + SAL_DLLPRIVATE sal_Bool ImplMakeMono( sal_uInt8 cThreshold ); SAL_DLLPRIVATE sal_Bool ImplMakeMonoDither(); SAL_DLLPRIVATE sal_Bool ImplMakeGreyscales( sal_uInt16 nGreyscales ); |