bool CResizeEngine::scale (CDIBSection *src, CDIBSection *dst, ILongTimeRunCallback *pCallback) {
assert(src != NULL && dst != NULL);
uint src_width = (uint)src->getWidth();
uint src_height = (uint)src->getHeight();
uint dst_width = (uint)dst->getWidth();
uint dst_height = (uint)dst->getHeight();
int bitcount = src->getBitCounts();
assert(dst_width > 0 && dst_height > 0);
assert(bitcount == 24 || bitcount == 32);
if (m_pFilter == NULL) {
_FastScale(src, dst);
return true;
}
if(dst_width * src_height <= dst_height * src_width) {
CDIBSectionPtr tmp = CDIBSection::createDIBSection(dst_width, src_height, bitcount, false);
if (!tmp) {
return false;
}
if (!horizontalFilter(src, src_height, tmp.get(), 0, src_height, pCallback)) {
assert(pCallback && pCallback->shouldStop());
return false;
}
if (!verticalFilter(tmp.get(), dst, pCallback)) {
assert(pCallback && pCallback->shouldStop());
return false;
}
} else {
CDIBSectionPtr tmp = CDIBSection::createDIBSection(src_width, dst_height, bitcount, false);
if (!tmp) {
return false;
}
if (!verticalFilter(src, tmp.get(), pCallback)) {
assert(pCallback && pCallback->shouldStop());
return false;
}
if (!horizontalFilter(tmp.get(), dst_height, dst, 0, dst_height, pCallback)) {
assert(pCallback && pCallback->shouldStop());
return false;
}
}
return true;
}
FIBITMAP* CResizeEngine::scale(FIBITMAP *src, unsigned dst_width, unsigned dst_height) {
DWORD src_width = FreeImage_GetWidth(src);
DWORD src_height = FreeImage_GetHeight(src);
unsigned redMask = FreeImage_GetRedMask(src);
unsigned greenMask = FreeImage_GetGreenMask(src);
unsigned blueMask = FreeImage_GetBlueMask(src);
unsigned bpp = FreeImage_GetBPP(src);
FREE_IMAGE_TYPE image_type = FreeImage_GetImageType(src);
// allocate the dst image
FIBITMAP *dst = FreeImage_AllocateT(image_type, dst_width, dst_height, bpp, redMask, greenMask, blueMask);
if(!dst) return NULL;
if(bpp == 8) {
if(FreeImage_GetColorType(src) == FIC_MINISWHITE) {
// build an inverted greyscale palette
RGBQUAD *dst_pal = FreeImage_GetPalette(dst);
for(int i = 0; i < 256; i++) {
dst_pal[i].rgbRed = dst_pal[i].rgbGreen =
dst_pal[i].rgbBlue = (BYTE)(255 - i);
}
} else {
// build a greyscale palette
RGBQUAD *dst_pal = FreeImage_GetPalette(dst);
for(int i = 0; i < 256; i++) {
dst_pal[i].rgbRed = dst_pal[i].rgbGreen =
dst_pal[i].rgbBlue = (BYTE)i;
}
}
}
// decide which filtering order (xy or yx) is faster for this mapping by
// counting convolution multiplies
if(dst_width*src_height <= dst_height*src_width) {
// xy filtering
// -------------
// allocate a temporary image
FIBITMAP *tmp = FreeImage_AllocateT(image_type, dst_width, src_height, bpp, redMask, greenMask, blueMask);
if(!tmp) {
FreeImage_Unload(dst);
return NULL;
}
// scale source image horizontally into temporary image
horizontalFilter(src, src_width, src_height, tmp, dst_width, src_height);
// scale temporary image vertically into result image
verticalFilter(tmp, dst_width, src_height, dst, dst_width, dst_height);
// free temporary image
FreeImage_Unload(tmp);
} else {
// yx filtering
// -------------
// allocate a temporary image
FIBITMAP *tmp = FreeImage_AllocateT(image_type, src_width, dst_height, bpp, redMask, greenMask, blueMask);
if(!tmp) {
FreeImage_Unload(dst);
return NULL;
}
// scale source image vertically into temporary image
verticalFilter(src, src_width, src_height, tmp, src_width, dst_height);
// scale temporary image horizontally into result image
horizontalFilter(tmp, src_width, dst_height, dst, dst_width, dst_height);
// free temporary image
FreeImage_Unload(tmp);
}
return dst;
}
