/**************************************************************************** * * dibmap.c * * Histrogram and optimal palette processing module. * * Microsoft Video for Windows Sample Capture Class * * Copyright (c) 1992, 1993 Microsoft Corporation. All Rights Reserved. * * You have a royalty-free right to use, modify, reproduce and * distribute the Sample Files (and/or any modified version) in * any way you find useful, provided that you agree that * Microsoft has no warranty obligations or liability for any * Sample Application Files which are modified. * ***************************************************************************/ #include #include #include "dibmap.h" #ifndef _WIN32 extern NEAR PASCAL MemCopy(LPVOID,LPVOID,DWORD); #endif extern NEAR PASCAL MemFill(LPVOID,DWORD,BYTE); void Histogram24(BYTE huge *pb, int dx, int dy, UINT WidthBytes, LPHISTOGRAM lpHistogram); void Histogram16(BYTE huge *pb, int dx, int dy, UINT WidthBytes, LPHISTOGRAM lpHistogram); void Histogram8(BYTE huge *pb, int dx, int dy, UINT WidthBytes, LPHISTOGRAM lpHistogram, LPWORD lpColors); void Histogram4(BYTE huge *pb, int dx, int dy, UINT WidthBytes, LPHISTOGRAM lpHistogram, LPWORD lpColors); void Histogram1(BYTE huge *pb, int dx, int dy, UINT WidthBytes, LPHISTOGRAM lpHistogram, LPWORD lpColors); void Reduce24(BYTE huge *pbIn, int dx, int dy, UINT cbIn, BYTE huge *pbOut, UINT cbOut, LPBYTE lp16to8); void Reduce16(BYTE huge *pbIn, int dx, int dy, UINT cbIn, BYTE huge *pbOut, UINT cbOut, LPBYTE lp16to8); void Reduce8(BYTE huge *pbIn, int dx, int dy, UINT cbIn, BYTE huge *pbOut, UINT cbOut, LPBYTE lp8to8); void Reduce4(BYTE huge *pbIn, int dx, int dy, UINT cbIn, BYTE huge *pbOut, UINT cbOut, LPBYTE lp8to8); void Reduce1(BYTE huge *pbIn, int dx, int dy, UINT cbIn, BYTE huge *pbOut, UINT cbOut, LPBYTE lp8to8); // // InitHistogram // // create a zero'ed histogram table, or initialize a existing table // to all zeros. // LPHISTOGRAM InitHistogram(LPHISTOGRAM lpHistogram) { if (lpHistogram == NULL) lpHistogram = (LPVOID)GlobalAllocPtr(GHND,32768l*sizeof(DWORD)); #if 0 if (lpHistogram) MemFill(lpHistogram, 32768l * sizeof(DWORD), 0); #endif return lpHistogram; } // // FreeHistogram // // free a histogram table // void FreeHistogram(LPHISTOGRAM lpHistogram) { GlobalFreePtr(lpHistogram); } // // DibHistogram // // take all colors in a dib and increment its entry in the Histogram table // // supports the following DIB formats: 1,4,8,16,24 // BOOL DibHistogram(LPBITMAPINFOHEADER lpbi, LPBYTE lpBits, int x, int y, int dx, int dy, LPHISTOGRAM lpHistogram) { int i; UINT WidthBytes; RGBQUAD FAR * prgbq; WORD argb16[256]; if (lpbi == NULL || lpHistogram == NULL) return FALSE; if (lpbi->biClrUsed == 0 && lpbi->biBitCount <= 8) lpbi->biClrUsed = (1 << (int)lpbi->biBitCount); if (lpBits == NULL) lpBits = (LPBYTE)lpbi + (int)lpbi->biSize + (int)lpbi->biClrUsed*sizeof(RGBQUAD); WidthBytes = (UINT)((lpbi->biBitCount * lpbi->biWidth + 7) / 8 + 3) & ~3; ((BYTE huge *)lpBits) += (DWORD)y*WidthBytes + ((x*(int)lpbi->biBitCount)/8); if (dx < 0 || dx > (int)lpbi->biWidth) dx = (int)lpbi->biWidth; if (dy < 0 || dy > (int)lpbi->biHeight) dy = (int)lpbi->biHeight; if ((int)lpbi->biBitCount <= 8) { prgbq = (LPVOID)((LPBYTE)lpbi + lpbi->biSize); for (i=0; i<(int)lpbi->biClrUsed; i++) { argb16[i] = RGB16(prgbq[i].rgbRed,prgbq[i].rgbGreen,prgbq[i].rgbBlue); } for (i=(int)lpbi->biClrUsed; i<256; i++) { argb16[i] = 0x0000; // just in case! } } switch ((int)lpbi->biBitCount) { case 24: Histogram24(lpBits, dx, dy, WidthBytes, lpHistogram); break; case 16: Histogram16(lpBits, dx, dy, WidthBytes, lpHistogram); break; case 8: Histogram8(lpBits, dx, dy, WidthBytes, lpHistogram, argb16); break; case 4: Histogram4(lpBits, dx, dy, WidthBytes, lpHistogram, argb16); break; case 1: Histogram1(lpBits, dx, dy, WidthBytes, lpHistogram, argb16); break; } } // // will convert the given DIB to a 8bit DIB with the specifed palette // HANDLE DibReduce(LPBITMAPINFOHEADER lpbiIn, LPBYTE pbIn, HPALETTE hpal, LPBYTE lp16to8) { HANDLE hdib; int nPalColors; int nDibColors; UINT cbOut; UINT cbIn; BYTE xlat[256]; BYTE HUGE * pbOut; RGBQUAD FAR * prgb; DWORD dwSize; int i; int dx; int dy; PALETTEENTRY pe; LPBITMAPINFOHEADER lpbiOut; dx = (int)lpbiIn->biWidth; dy = (int)lpbiIn->biHeight; cbIn = ((lpbiIn->biBitCount*dx+7)/8+3)&~3; cbOut = (dx+3)&~3; #ifdef _WIN32 // careful with GetObject in Win32: this (counter-intuitively) writes // a short not an INT for the number of colours // (despite being passed a 32 bit variable) // BUT the code uses INTs more efficiently // So we must initialize the variable to 0 to clear the high 16bits nPalColors = 0; #endif GetObject(hpal, sizeof(nPalColors), (LPVOID)&nPalColors); nDibColors = (int)lpbiIn->biClrUsed; if (nDibColors == 0 && lpbiIn->biBitCount <= 8) nDibColors = (1 << (int)lpbiIn->biBitCount); if (pbIn == NULL) pbIn = (LPBYTE)lpbiIn + (int)lpbiIn->biSize + nDibColors*sizeof(RGBQUAD); dwSize = (DWORD)cbOut * dy; hdib = GlobalAlloc(GMEM_MOVEABLE,sizeof(BITMAPINFOHEADER) + nPalColors*sizeof(RGBQUAD) + dwSize); if (!hdib) return NULL; lpbiOut = (LPVOID)GlobalLock(hdib); lpbiOut->biSize = sizeof(BITMAPINFOHEADER); lpbiOut->biWidth = lpbiIn->biWidth; lpbiOut->biHeight = lpbiIn->biHeight; lpbiOut->biPlanes = 1; lpbiOut->biBitCount = 8; lpbiOut->biCompression = BI_RGB; lpbiOut->biSizeImage = dwSize; lpbiOut->biXPelsPerMeter= 0; lpbiOut->biYPelsPerMeter= 0; lpbiOut->biClrUsed = nPalColors; lpbiOut->biClrImportant = 0; pbOut = (LPBYTE)lpbiOut + (int)lpbiOut->biSize + nPalColors*sizeof(RGBQUAD); prgb = (LPVOID)((LPBYTE)lpbiOut + (int)lpbiOut->biSize); for (i=0; ibiBitCount <= 8) { prgb = (LPVOID)((LPBYTE)lpbiIn + lpbiIn->biSize); for (i=0; ibiBitCount) { case 24: Reduce24(pbIn, dx, dy, cbIn, pbOut, cbOut, lp16to8); break; case 16: Reduce16(pbIn, dx, dy, cbIn, pbOut, cbOut, lp16to8); break; case 8: Reduce8(pbIn, dx, dy, cbIn, pbOut, cbOut, xlat); break; case 4: Reduce4(pbIn, dx, dy, cbIn, pbOut, cbOut, xlat); break; case 1: Reduce1(pbIn, dx, dy, cbIn, pbOut, cbOut, xlat); break; } return hdib; } /////////////////////////////////////////////////////////////////////////////// // cluster.c /////////////////////////////////////////////////////////////////////////////// #define IN_DEPTH 5 // # bits/component kept from input #define IN_SIZE (1 << IN_DEPTH) // max value of a color component typedef enum { red, green, blue } color; typedef struct tagCut { int cutpoint; color cutaxis; } Cut; typedef struct tagColorBox { // from cluster.c struct tagColorBox *next; /* pointer to next box */ int rmin, rmax, gmin, gmax, bmin, bmax; /* bounding box */ long variance, wt; /* weighted variance */ long sum[3]; /* sum of values */ } ColorBox; static int InitBoxes(int nBoxes); static void DeleteBoxes(void); static int SplitBoxAxis(ColorBox *box, Cut cutaxis); static void ShrinkBox(ColorBox *box); static int ComputePalette(LPHISTOGRAM lpHistogram, LPBYTE lp16to8, LPPALETTEENTRY palette); static COLORREF DetermineRepresentative(ColorBox *box, int palIndex); static Cut FindSplitAxis(ColorBox *box); static void SplitBox(ColorBox *box); static void SortBoxes(void); HANDLE hBoxes; ColorBox *UsedBoxes; ColorBox *FreeBoxes; LPBYTE glp16to8; #ifdef _WIN32 /* * to avoid all this 16 bit assembler with minimal changes to the * rest of the code the Win32 version will use a global pointer set by * UseHistogram and accessed by the hist() and IncHistogram macros. */ DWORD HUGE* glpHistogram; #define UseHistogram(p) (glpHistogram = (p)) #define hist(r,g,b) ((DWORD HUGE *)glpHistogram)[(WORD)(b) | ((WORD)(g)<64k histogram counts. // !!!fix this // for (dwMax=0,w=0; w<0x8000; w++) dwMax = max(dwMax,lpHistogram[w]); while (dwMax > 0xFFFFl) { for (w=0; w<0x8000; w++) lpHistogram[w] /= 2; dwMax /= 2; } if (!InitBoxes(min(nColors, 236))) return NULL; UseHistogram(lpHistogram); glp16to8 = lp16to8; /* while there are free boxes left, split the largest */ i = 0; do { i++; SplitBox(UsedBoxes); } while (FreeBoxes && UsedBoxes->variance); SortBoxes(); i=0; // // add some standard colors to the histogram // if (nColors > 236) { HDC hdc; HPALETTE hpal; hdc = GetDC(NULL); if (GetDeviceCaps(hdc, RASTERCAPS) & RC_PALETTE) { GetSystemPaletteEntries(hdc, 0, 10, &pal.palPalEntry[0]); GetSystemPaletteEntries(hdc, 246, 10, &pal.palPalEntry[246]); i = 10; } else { // we're a true colour device, so get the system // colours from the default palette. hpal = GetStockObject(DEFAULT_PALETTE); GetPaletteEntries(hpal, 0, 10, &pal.palPalEntry[0]); GetPaletteEntries(hpal, 10, 10, &pal.palPalEntry[246]); i = 10; } ReleaseDC(NULL, hdc); } // probably not needed on C-only versions (NT). UseHistogram(lpHistogram); // Register FS trashed by above! /* Generate the representitives and the associated Palette mapping */ /* NOTE: Might loop less than nColors times. */ for (box = UsedBoxes; box; box = box->next, i++) { rgb = DetermineRepresentative(box, i); pal.palPalEntry[i].peRed = GetRValue(rgb); pal.palPalEntry[i].peGreen = GetGValue(rgb); pal.palPalEntry[i].peBlue = GetBValue(rgb); pal.palPalEntry[i].peFlags = 0; } DeleteBoxes(); if (nColors > 236) { for (; i<246; i++) { pal.palPalEntry[i].peRed = 0; pal.palPalEntry[i].peGreen = 0; pal.palPalEntry[i].peBlue = 0; pal.palPalEntry[i].peFlags = 0; } i = 256; } glp16to8 = NULL; pal.palVersion = 0x300; pal.palNumEntries = i; return CreatePalette((LPLOGPALETTE)&pal); } #pragma optimize ("", on) static void SortBoxes() { ColorBox *box; ColorBox *newList; ColorBox *insBox; ColorBox *nextBox; newList = UsedBoxes; nextBox = newList->next; newList->next = NULL; for (box = nextBox; box; box = nextBox) { // just an insertion sort... nextBox = box->next; if (box->wt > newList->wt) { box->next = newList; newList = box; } else { for (insBox = newList; insBox->next && (box->wt < insBox->next->wt); insBox = insBox->next) ; box->next = insBox->next; insBox->next = box; } } UsedBoxes = newList; } /* allocate space for nBoxes boxes, set up links. On exit UsedBoxes points to one box, FreeBoxes points to remaining (nBoxes-1) boxes. return 0 if successful. */ static BOOL InitBoxes(int nBoxes) { int i; hBoxes = LocalAlloc(LHND, nBoxes*sizeof(ColorBox)); if (!hBoxes) return FALSE; UsedBoxes = (ColorBox*)LocalLock(hBoxes); FreeBoxes = UsedBoxes + 1; UsedBoxes->next = NULL; for (i = 0; i < nBoxes - 1; ++i) { FreeBoxes[i].next = FreeBoxes + i + 1; } FreeBoxes[nBoxes-2].next = NULL; /* save the bounding box */ UsedBoxes->rmin = UsedBoxes->gmin = UsedBoxes->bmin = 0; UsedBoxes->rmax = UsedBoxes->gmax = UsedBoxes->bmax = IN_SIZE - 1; UsedBoxes->variance = 9999999; /* arbitrary large # */ return TRUE; } static void DeleteBoxes() { LocalUnlock(hBoxes); LocalFree(hBoxes); hBoxes = NULL; } static void SplitBox(ColorBox *box) { /* split box into two roughly equal halves and update the data structures appropriately. */ Cut cutaxis; ColorBox *temp, *temp2, *prev; cutaxis = FindSplitAxis(box); /* split the box along that axis. If rc != 0 then the box contains one color, and should not be split */ if (SplitBoxAxis(box, cutaxis)) return; /* shrink each of the boxes to fit the points they enclose */ ShrinkBox(box); ShrinkBox(FreeBoxes); /* move old box down in list, if necessary */ if (box->next && box->variance < box->next->variance) { UsedBoxes = box->next; temp = box; do { prev = temp; temp = temp->next; } while (temp && temp->variance > box->variance); box->next = temp; prev->next = box; } /* insert the new box in sorted order (descending), removing it from the free list. */ if (FreeBoxes->variance >= UsedBoxes->variance) { temp = FreeBoxes; FreeBoxes = FreeBoxes->next; temp->next = UsedBoxes; UsedBoxes = temp; } else { temp = UsedBoxes; do { prev = temp; temp = temp->next; } while (temp && temp->variance > FreeBoxes->variance); temp2 = FreeBoxes->next; FreeBoxes->next = temp; prev->next = FreeBoxes; FreeBoxes = temp2; } } static Cut FindSplitAxis(ColorBox *box) { unsigned long proj_r[IN_SIZE],proj_g[IN_SIZE],proj_b[IN_SIZE]; unsigned long f; double currentMax,mean; unsigned long w,w1,m,m1; short r,g,b; short bestCut; color bestAxis; Cut cutRet; double temp1,temp2; for (r = 0; r < IN_SIZE; r++) { proj_r[r] = proj_g[r] = proj_b[r] = 0; } w = 0; // Project contents of box down onto axes for (r = box->rmin; r <= box->rmax; r++) { for (g = box->gmin; g <= box->gmax; ++g) { for (b = box->bmin; b <= box->bmax; ++b) { f = hist(r,g,b); proj_r[r] += f; proj_g[g] += f; proj_b[b] += f; } } w += proj_r[r]; } currentMax = 0.0f; #define Check_Axis(l,color) \ m = 0; \ for (l = box->l##min; l <= box->l##max; (l)++) { \ m += l * proj_##l[l]; \ } \ mean = ((double) m) / ((double) w); \ \ w1 = 0; \ m1 = 0; \ for (l = box->l##min; l <= box->l##max; l++) { \ w1 += proj_##l[l]; \ if (w1 == 0) \ continue; \ if (w1 == w) \ break; \ m1 += l * proj_##l[l]; \ temp1 = mean - (((double) m1) / ((double) w1)); \ temp2 = (((double) w1) / ((double) (w-w1))) * temp1 * temp1; \ if (temp2 > currentMax) { \ bestCut = l; \ bestAxis = color; \ currentMax = temp2; \ } \ } Check_Axis(r,red); Check_Axis(g,green); Check_Axis(b,blue); cutRet.cutaxis = bestAxis; cutRet.cutpoint = bestCut; return cutRet; } static int SplitBoxAxis(ColorBox *box, Cut cutaxis) { /* Split box along splitaxis into two boxes, one of which is placed back in box, the other going in the first free box (FreeBoxes) If the box only contains one color, return non-zero, else return 0. */ ColorBox *next; if ( box->variance == 0) return 1; /* copy all non-link information to new box */ next = FreeBoxes->next; *FreeBoxes = *box; FreeBoxes->next = next; switch (cutaxis.cutaxis) { case red: box->rmax = cutaxis.cutpoint; FreeBoxes->rmin = cutaxis.cutpoint+1; break; case green: box->gmax = cutaxis.cutpoint; FreeBoxes->gmin = cutaxis.cutpoint+1; break; case blue: box->bmax = cutaxis.cutpoint; FreeBoxes->bmin = cutaxis.cutpoint+1; break; } return 0; } static void ShrinkBox(ColorBox *box) { unsigned long n, sxx, sx2, var, quotient, remainder; int r,g,b; unsigned long f; unsigned long proj_r[IN_SIZE],proj_g[IN_SIZE],proj_b[IN_SIZE]; n = 0; for (r = 0; r < IN_SIZE; r++) { proj_r[r] = proj_g[r] = proj_b[r] = 0; } // Project contents of box down onto axes for (r = box->rmin; r <= box->rmax; r++) { for (g = box->gmin; g <= box->gmax; ++g) { for (b = box->bmin; b <= box->bmax; ++b) { f = hist(r,g,b); proj_r[r] += f; proj_g[g] += f; proj_b[b] += f; } } n += proj_r[r]; } box->wt = n; var = 0; #define AddAxisVariance(c) \ sxx = 0; sx2 = 0; \ for (c = box->c##min; c <= box->c##max; c++) { \ sxx += proj_##c[c] * c * c; \ sx2 += proj_##c[c] * c; \ } \ quotient = sx2 / n; /* This stuff avoids overflow */ \ remainder = sx2 % n; \ var += sxx - quotient * sx2 - ((remainder * sx2)/n); AddAxisVariance(r); AddAxisVariance(g); AddAxisVariance(b); box->variance = var; } static COLORREF DetermineRepresentative(ColorBox *box, int palIndex) { /* determines the rgb value to represent the pixels contained in box. nbits is the # bits/component we're allowed to return. */ long f; long Rval, Gval, Bval; unsigned long total; int r, g, b; UINT w; /* compute the weighted sum of the elements in the box */ Rval = Gval = Bval = total = 0; for (r = box->rmin; r <= box->rmax; ++r) { for (g = box->gmin; g <= box->gmax; ++g) { for (b = box->bmin; b <= box->bmax; ++b) { if (glp16to8) { w = (UINT)(b) | ((WORD)(g)<>4]; IncHistogram(w); w = lpColors[b&0x0F]; IncHistogram(w); } pb += WidthBytes; } } void Histogram1(BYTE HUGE *pb, int dx, int dy, UINT WidthBytes, LPHISTOGRAM lpHistogram, LPWORD lpColors) { int x,y,i; BYTE b; UINT w; UseHistogram(lpHistogram); WidthBytes -= (dx+7)/8; for (y=0; y>7]; IncHistogram(w); b<<=1; } } pb += WidthBytes; } } /////////////////////////////////////////////////////////////////////////////// // // write this stuff in ASM! too // -- if you do - please leave the C version #ifdef _WIN32 // /////////////////////////////////////////////////////////////////////////////// void Reduce24(BYTE HUGE *pbIn, int dx, int dy, UINT cbIn, BYTE HUGE *pbOut, UINT cbOut, LPBYTE lp16to8) { int x,y; BYTE r,g,b; cbOut -= dx; cbIn -= dx*3; for (y=0; y>4]; *pbOut++ = lp8to8[b&0x0F]; } pbIn += cbIn; pbOut += cbOut; } } void Reduce1(BYTE HUGE *pbIn, int dx, int dy, UINT cbIn, BYTE HUGE *pbOut, UINT cbOut, LPBYTE lp8to8) { int x,y; BYTE b; cbIn -= (dx+7)/8; cbOut -= dx; for (y=0; y>7]; b<<=1; } pbIn += cbIn; pbOut += cbOut; } }