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// ==========================================================
// LFPQuantizer class implementation
//
// Design and implementation by
// - Carsten Klein (cklein05@users.sourceforge.net)
//
// This file is part of FreeImage 3
//
// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES
// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE
// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED
// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT
// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY
// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL
// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER
// THIS DISCLAIMER.
//
// Use at your own risk!
// ==========================================================
#include "Quantizers.h"
#include "FreeImage.h"
#include "Utilities.h"
LFPQuantizer::LFPQuantizer(unsigned PaletteSize) :
m_size(0), m_limit(PaletteSize), m_index(0) {
m_map = new MapEntry[MAP_SIZE];
memset(m_map, 0xFF, MAP_SIZE * sizeof(MapEntry));
}
LFPQuantizer::~LFPQuantizer() {
delete[] m_map;
}
FIBITMAP* LFPQuantizer::Quantize(FIBITMAP *dib, int ReserveSize, RGBQUAD *ReservePalette) {
if (ReserveSize > 0 && ReservePalette != NULL) {
AddReservePalette(ReservePalette, ReserveSize);
}
const unsigned width = FreeImage_GetWidth(dib);
const unsigned height = FreeImage_GetHeight(dib);
FIBITMAP *dib8 = FreeImage_Allocate(width, height, 8);
if (dib8 == NULL) {
return NULL;
}
const unsigned src_pitch = FreeImage_GetPitch(dib);
const unsigned dst_pitch = FreeImage_GetPitch(dib8);
const BYTE * const src_bits = FreeImage_GetBits(dib);
BYTE * const dst_bits = FreeImage_GetBits(dib8);
unsigned last_color = -1;
int last_index = 0;
if (FreeImage_GetBPP(dib) == 24) {
// Getting the source pixel as an unsigned int is much faster than
// working with FI_RGBA_xxx and shifting. However, this may fail
// for the very last pixel, since its rgbReserved member (alpha)
// may actually point to an address beyond the bitmap's memory. So,
// we do not process the last scanline in the first loop.
// Process all but the last scanline.
for (unsigned y = 0; y < height - 1; ++y) {
BYTE *dst_line = dst_bits + y * dst_pitch;
const BYTE *src_line = src_bits + y * src_pitch;
for (unsigned x = 0; x < width; ++x) {
const unsigned color = *((unsigned *) src_line) & 0x00FFFFFF;
if (color != last_color) {
last_color = color;
last_index = GetIndexForColor(color);
if (last_index == -1) {
FreeImage_Unload(dib8);
return NULL;
}
}
dst_line[x] = last_index;
src_line += 3;
}
}
// Process all but the last pixel of the last scanline.
BYTE *dst_line = dst_bits + (height - 1) * dst_pitch;
const BYTE *src_line = src_bits + (height - 1) * src_pitch;
for (unsigned x = 0; x < width - 1; ++x) {
const unsigned color = *((unsigned *) src_line) & 0x00FFFFFF;
if (color != last_color) {
last_color = color;
last_index = GetIndexForColor(color);
if (last_index == -1) {
FreeImage_Unload(dib8);
return NULL;
}
}
dst_line[x] = last_index;
src_line += 3;
}
// Process the last pixel (src_line should already point to it).
const unsigned color = 0 | src_line[FI_RGBA_BLUE] << FI_RGBA_BLUE_SHIFT
| src_line[FI_RGBA_GREEN] << FI_RGBA_GREEN_SHIFT
| src_line[FI_RGBA_RED] << FI_RGBA_RED_SHIFT;
if (color != last_color) {
last_color = color;
last_index = GetIndexForColor(color);
if (last_index == -1) {
FreeImage_Unload(dib8);
return NULL;
}
}
dst_line[width - 1] = last_index;
} else {
for (unsigned y = 0; y < height; ++y) {
BYTE *dst_line = dst_bits + y * dst_pitch;
const BYTE *src_line = src_bits + y * src_pitch;
for (unsigned x = 0; x < width; ++x) {
const unsigned color = *((unsigned *) src_line) & 0x00FFFFFF;
if (color != last_color) {
last_color = color;
last_index = GetIndexForColor(color);
if (last_index == -1) {
FreeImage_Unload(dib8);
return NULL;
}
}
dst_line[x] = last_index;
src_line += 4;
}
}
}
WritePalette(FreeImage_GetPalette(dib8));
return dib8;
}
/**
* Returns the palette index of the specified color. Tries to put the
* color into the map, if it's not already present in the map. In that
* case, a new index is used for the color. Returns -1, if adding the
* color would exceed the desired maximum number of colors in the
* palette.
* @param color the color to get the index from
* @return the palette index of the specified color or -1, if there
* is no space left in the palette
*/
inline int LFPQuantizer::GetIndexForColor(unsigned color) {
unsigned bucket = hash(color) & (MAP_SIZE - 1);
while (m_map[bucket].color != color) {
if (m_map[bucket].color == EMPTY_BUCKET) {
if (m_size == m_limit) {
return -1;
}
m_map[bucket].color = color;
m_map[bucket].index = m_index++;
++m_size;
break;
}
bucket = (bucket + 1) % MAP_SIZE;
}
return m_map[bucket].index;
}
/**
* Adds the specified number of entries of the specified reserve
* palette to the newly created palette.
* @param *palette a pointer to the reserve palette to copy from
* @param size the number of entries to copy
*/
void LFPQuantizer::AddReservePalette(const void *palette, unsigned size) {
if (size > MAX_SIZE) {
size = MAX_SIZE;
}
unsigned *ppal = (unsigned *) palette;
const unsigned offset = m_limit - size;
for (unsigned i = 0; i < size; ++i) {
const unsigned color = *ppal++;
const unsigned index = i + offset;
unsigned bucket = hash(color) & (MAP_SIZE - 1);
while((m_map[bucket].color != EMPTY_BUCKET) && (m_map[bucket].color != color)) {
bucket = (bucket + 1) % MAP_SIZE;
}
if(m_map[bucket].color != color) {
m_map[bucket].color = color;
m_map[bucket].index = index;
}
}
m_size += size;
}
/**
* Copies the newly created palette into the specified destination
* palette. Although unused palette entries are not overwritten in
* the destination palette, it is assumed to have space for at
* least 256 entries.
* @param palette a pointer to the destination palette
*/
void LFPQuantizer::WritePalette(void *palette) {
for (unsigned i = 0; i < MAP_SIZE; ++i) {
if (m_map[i].color != EMPTY_BUCKET) {
((unsigned *) palette)[m_map[i].index] = m_map[i].color;
}
}
}
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