From: Rudolf Polzer Date: Fri, 17 Sep 2010 15:55:34 +0000 (+0200) Subject: support more filters; a (currently C99-only) way to invert discrete convolutions X-Git-Tag: xonotic-v0.1.0preview~204 X-Git-Url: https://git.xonotic.org/?p=xonotic%2Fxonotic.git;a=commitdiff_plain;h=64a00f88fef521af988751f300b4b485e58de938 support more filters; a (currently C99-only) way to invert discrete convolutions --- diff --git a/misc/tools/fft-normalmap-to-heightmap.c b/misc/tools/fft-normalmap-to-heightmap.c index 8d95d5c6..7b72fcbd 100644 --- a/misc/tools/fft-normalmap-to-heightmap.c +++ b/misc/tools/fft-normalmap-to-heightmap.c @@ -35,10 +35,11 @@ #define TWO_PI (4*atan2(1,1) * 2) -void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, double scale, double offset) +void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, double scale, double offset, const double *filter, int filterw, int filterh) { int x, y; - int fx, fy; + int i, j; + double fx, fy; double ffx, ffy; double nx, ny, nz; double v, vmin, vmax; @@ -88,34 +89,72 @@ void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, for(y = 0; y < h; ++y) for(x = 0; x < w; ++x) { - fx = x; - fy = y; - if(fx > w/2) - fx -= w; - if(fy > h/2) - fy -= h; - /* these must have the same sign as fx and fy (so ffx*fx + ffy*fy is nonzero), otherwise do not matter */ - /* it basically decides how artifacts are distributed */ - ffx = fx; - ffy = fy; + fx = x * 1.0 / w; + fy = y * 1.0 / h; + if(filter) + { + // discontinous case + // we must invert whatever "filter" would do on (x, y)! #ifdef C99 - if(fx||fy) - freqspace1[(w*y+x)] = _Complex_I * (ffx * freqspace1[(w*y+x)] + ffy * freqspace2[(w*y+x)]) / (ffx*fx + ffy*fy) / TWO_PI; - else - freqspace1[(w*y+x)] = 0; + fftw_complex response_x = 0; + fftw_complex response_y = 0; + double sum; + for(i = -filterh / 2; i <= filterh / 2; ++i) + for(j = -filterw / 2; j <= filterw / 2; ++j) + { + response_x += filter[(i + filterh / 2) * filterw + j + filterw / 2] * cexp(-_Complex_I * TWO_PI * (j * fx + i * fy)); + response_y += filter[(i + filterh / 2) * filterw + j + filterw / 2] * cexp(-_Complex_I * TWO_PI * (i * fx + j * fy)); + } + + // we know: + // fourier(df/dx)_xy = fourier(f)_xy * response_x + // fourier(df/dy)_xy = fourier(f)_xy * response_y + // mult by conjugate of response_x, response_y: + // conj(response_x) * fourier(df/dx)_xy = fourier(f)_xy * |response_x^2| + // conj(response_y) * fourier(df/dy)_xy = fourier(f)_xy * |response_y^2| + // and + // fourier(f)_xy = (conj(response_x) * fourier(df/dx)_xy + conj(response_y) * fourier(df/dy)_xy) / (|response_x|^2 + |response_y|^2) + + sum = cabs(response_x) * cabs(response_x) + cabs(response_y) * cabs(response_y); + + if(sum > 0) + freqspace1[(w*y+x)] = (conj(response_x) * freqspace1[(w*y+x)] + conj(response_y) * freqspace2[(w*y+x)]) / sum; + else + freqspace1[(w*y+x)] = 0; #else - if(fx||fy) - { - save = freqspace1[(w*y+x)][0]; - freqspace1[(w*y+x)][0] = -(ffx * freqspace1[(w*y+x)][1] + ffy * freqspace2[(w*y+x)][1]) / (ffx*fx + ffy*fy) / TWO_PI; - freqspace1[(w*y+x)][1] = (ffx * save + ffy * freqspace2[(w*y+x)][0]) / (ffx*fx + ffy*fy) / TWO_PI; + // not yet implemented +#endif } else { - freqspace1[(w*y+x)][0] = 0; - freqspace1[(w*y+x)][1] = 0; - } + // continuous integration case + if(fx > 0.5) + fx -= 1; + if(fy > 0.5) + fy -= 1; + /* these must have the same sign as fx and fy (so ffx*fx + ffy*fy is nonzero), otherwise do not matter */ + /* it basically decides how artifacts are distributed */ + ffx = fx; + ffy = fy; +#ifdef C99 + if(fx||fy) + freqspace1[(w*y+x)] = _Complex_I * (ffx * freqspace1[(w*y+x)] + ffy * freqspace2[(w*y+x)]) / (ffx*fx + ffy*fy) / TWO_PI; + else + freqspace1[(w*y+x)] = 0; +#else + if(fx||fy) + { + save = freqspace1[(w*y+x)][0]; + freqspace1[(w*y+x)][0] = -(ffx * freqspace1[(w*y+x)][1] + ffy * freqspace2[(w*y+x)][1]) / (ffx*fx + ffy*fy) / TWO_PI; + freqspace1[(w*y+x)][1] = (ffx * save + ffy * freqspace2[(w*y+x)][0]) / (ffx*fx + ffy*fy) / TWO_PI; + } + else + { + freqspace1[(w*y+x)][0] = 0; + freqspace1[(w*y+x)][1] = 0; + } #endif + } } fftw_execute(f12i1); @@ -126,10 +165,10 @@ void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, for(x = 0; x < w; ++x) { #ifdef C99 - v = creal(imgspace1[(w*y+x)] /= (w*h)); + v = creal(imgspace1[(w*y+x)] /= pow(w*h, 1.5)); #else - v = (imgspace1[(w*y+x)][0] /= (w*h)); - imgspace1[(w*y+x)][1] /= (w*h); + v = (imgspace1[(w*y+x)][0] /= pow(w*h, 1.5)); + imgspace1[(w*y+x)][1] /= pow(w*h, 1.5); #endif if(v < vmin || (x == 0 && y == 0)) vmin = v; @@ -231,6 +270,7 @@ void nmap_to_hmap(unsigned char *map, const unsigned char *refmap, int w, int h, void hmap_to_nmap(unsigned char *map, int w, int h, int src_chan, double scale) { int x, y; + double fx, fy; double nx, ny, nz; double v; #ifndef C99 @@ -282,26 +322,32 @@ void hmap_to_nmap(unsigned char *map, int w, int h, int src_chan, double scale) for(y = 0; y < h; ++y) for(x = 0; x < w; ++x) { - int fx = x; - int fy = y; + fx = x; + fy = y; if(fx > w/2) fx -= w; if(fy > h/2) fy -= h; +#ifdef DISCONTINUOUS + fx = sin(fx * TWO_PI / w); + fy = sin(fy * TWO_PI / h); +#else #ifdef C99 /* a lowpass to prevent the worst */ freqspace1[(w*y+x)] *= 1 - pow(abs(fx) / (double)(w/2), 1); freqspace1[(w*y+x)] *= 1 - pow(abs(fy) / (double)(h/2), 1); - - freqspace2[(w*y+x)] = TWO_PI*_Complex_I * fy * freqspace1[(w*y+x)]; /* y derivative */ - freqspace1[(w*y+x)] = TWO_PI*_Complex_I * fx * freqspace1[(w*y+x)]; /* x derivative */ #else /* a lowpass to prevent the worst */ freqspace1[(w*y+x)][0] *= 1 - pow(abs(fx) / (double)(w/2), 1); freqspace1[(w*y+x)][1] *= 1 - pow(abs(fx) / (double)(w/2), 1); freqspace1[(w*y+x)][0] *= 1 - pow(abs(fy) / (double)(h/2), 1); freqspace1[(w*y+x)][1] *= 1 - pow(abs(fy) / (double)(h/2), 1); - +#endif +#endif +#ifdef C99 + freqspace2[(w*y+x)] = TWO_PI*_Complex_I * fy * freqspace1[(w*y+x)]; /* y derivative */ + freqspace1[(w*y+x)] = TWO_PI*_Complex_I * fx * freqspace1[(w*y+x)]; /* x derivative */ +#else freqspace2[(w*y+x)][0] = -TWO_PI * fy * freqspace1[(w*y+x)][1]; /* y derivative */ freqspace2[(w*y+x)][1] = TWO_PI * fy * freqspace1[(w*y+x)][0]; save = freqspace1[(w*y+x)][0]; @@ -348,19 +394,13 @@ void hmap_to_nmap(unsigned char *map, int w, int h, int src_chan, double scale) fftw_free(imgspace1); } -void hmap_to_nmap_local(unsigned char *map, int w, int h, int src_chan, double scale) +void hmap_to_nmap_local(unsigned char *map, int w, int h, int src_chan, double scale, const double *filter, int filterw, int filterh) { int x, y; double nx, ny, nz; double v; int i, j; double *img_reduced = malloc(w*h * sizeof(double)); - static const double filter[3][3] = { /* filter to derive one component */ - { -3, 0, 3 }, - { -10, 0, 10 }, - { -3, 0, 3 } - }; - static const double filter_mult = 0.03125; for(y = 0; y < h; ++y) for(x = 0; x < w; ++x) @@ -390,14 +430,14 @@ void hmap_to_nmap_local(unsigned char *map, int w, int h, int src_chan, double s for(y = 0; y < h; ++y) for(x = 0; x < w; ++x) { - nz = -1 / (scale * filter_mult); + nz = -1 / scale; nx = ny = 0; - for(i = -(int)(sizeof(filter) / sizeof(*filter)) / 2; i <= (int)(sizeof(filter) / sizeof(*filter)) / 2; ++i) - for(j = -(int)(sizeof(*filter) / sizeof(**filter)) / 2; j <= (int)(sizeof(*filter) / sizeof(**filter)) / 2; ++j) + for(i = -filterh / 2; i <= filterh / 2; ++i) + for(j = -filterw / 2; j <= filterw / 2; ++j) { - nx += img_reduced[w*((y+i+h)%h)+(x+j+w)%w] * filter[i+(sizeof(filter) / sizeof(*filter)) / 2][j+(sizeof(*filter) / sizeof(**filter)) / 2]; - ny += img_reduced[w*((y+j+h)%h)+(x+i+w)%w] * filter[i+(sizeof(filter) / sizeof(*filter)) / 2][j+(sizeof(*filter) / sizeof(**filter)) / 2]; + nx += img_reduced[w*((y+i+h)%h)+(x+j+w)%w] * filter[(i + filterh / 2) * filterw + j + filterw / 2]; + ny += img_reduced[w*((y+j+h)%h)+(x+i+w)%w] * filter[(i + filterh / 2) * filterw + j + filterw / 2]; } v = -sqrt(nx*nx + ny*ny + nz*nz); @@ -896,28 +936,74 @@ int Image_WriteTGABGRA (const char *filename, int width, int height, const unsig int usage(const char *me) { - printf("Usage: %s [ [ []]] (get heightmap from normalmap)\n", me); - printf("or: %s -1 [] (read from B, Diff)\n", me); - printf("or: %s -2 [] (read from G, Diff)\n", me); - printf("or: %s -3 [] (read from R, Diff)\n", me); - printf("or: %s -4 [] (read from A, Diff)\n", me); - printf("or: %s -5 [] (read from (R+G+B)/3, Diff)\n", me); - printf("or: %s -6 [] (read from Y, Diff)\n", me); - printf("or: %s -7 [] (read from B, FFT)\n", me); - printf("or: %s -8 [] (read from G, FFT)\n", me); - printf("or: %s -9 [] (read from R, FFT)\n", me); - printf("or: %s -10 [] (read from A, FFT)\n", me); - printf("or: %s -11 [] (read from (R+G+B)/3, FFT)\n", me); - printf("or: %s -12 [] (read from Y, FFT)\n", me); + printf("Usage: %s filtertype [ [ []]] (get heightmap from normalmap)\n", me); + printf("or: %s filtertype -1 [] (read from B)\n", me); + printf("or: %s filtertype -2 [] (read from G)\n", me); + printf("or: %s filtertype -3 [] (read from R)\n", me); + printf("or: %s filtertype -4 [] (read from A)\n", me); + printf("or: %s filtertype -5 [] (read from (R+G+B)/3)\n", me); + printf("or: %s filtertype -6 [] (read from Y)\n", me); return 1; } +static const double filter_scharr3[3][3] = { + { -3/32.0, 0, 3/32.0 }, + { -10/32.0, 0, 10/32.0 }, + { -3/32.0, 0, 3/32.0 } +}; + +static const double filter_prewitt3[3][3] = { + { -1/6.0, 0, 1/6.0 }, + { -1/6.0, 0, 1/6.0 }, + { -1/6.0, 0, 1/6.0 } +}; + +// pathologic for inverting +static const double filter_sobel3[3][3] = { + { -1/8.0, 0, 1/8.0 }, + { -2/8.0, 0, 2/8.0 }, + { -1/8.0, 0, 1/8.0 } +}; + +// pathologic for inverting +static const double filter_sobel5[5][5] = { + { -1/128.0, -2/128.0, 0, 2/128.0, 1/128.0 }, + { -4/128.0, -8/128.0, 0, 8/128.0, 4/128.0 }, + { -6/128.0, -12/128.0, 0, 12/128.0, 6/128.0 }, + { -4/128.0, -8/128.0, 0, 8/128.0, 4/128.0 }, + { -1/128.0, -2/128.0, 0, 2/128.0, 1/128.0 } +}; + +// pathologic for inverting +static const double filter_prewitt5[5][5] = { + { -1/40.0, -2/40.0, 0, 2/40.0, 1/40.0 }, + { -1/40.0, -2/40.0, 0, 2/40.0, 1/40.0 }, + { -1/40.0, -2/40.0, 0, 2/40.0, 1/40.0 }, + { -1/40.0, -2/40.0, 0, 2/40.0, 1/40.0 }, + { -1/40.0, -2/40.0, 0, 2/40.0, 1/40.0 } +}; + +static const double filter_trivial[1][3] = { + { -0.5, 0, 0.5 } +}; + int main(int argc, char **argv) { const char *infile, *outfile, *reffile; double scale, offset; int nmaplen, w, h; unsigned char *nmapdata, *nmap, *refmap; + const char *filtertype; + const double *filter = NULL; + int filterw = 0, filterh = 0; +#define USE_FILTER(f) \ + do \ + { \ + filterw = sizeof(*(f)) / sizeof(**(f)); \ + filterh = sizeof((f)) / sizeof(*(f)); \ + filter = &(f)[0][0]; \ + } \ + while(0) if(argc > 1) infile = argv[1]; @@ -930,17 +1016,22 @@ int main(int argc, char **argv) return usage(*argv); if(argc > 3) - scale = atof(argv[3]); + filtertype = argv[3]; + else + return usage(*argv); + + if(argc > 4) + scale = atof(argv[4]); else scale = 0; - if(argc > 4) - offset = atof(argv[4]); + if(argc > 5) + offset = atof(argv[5]); else offset = (scale<0) ? 1 : 0; - if(argc > 5) - reffile = argv[5]; + if(argc > 6) + reffile = argv[6]; else reffile = NULL; @@ -984,12 +1075,29 @@ int main(int argc, char **argv) else refmap = NULL; - if(scale < -6) - hmap_to_nmap(nmap, image_width, image_height, -scale-7, offset); - else if(scale < 0) - hmap_to_nmap_local(nmap, image_width, image_height, -scale-1, offset); + if(!strcmp(filtertype, "trivial")) + USE_FILTER(filter_trivial); + if(!strcmp(filtertype, "prewitt3")) + USE_FILTER(filter_prewitt3); + if(!strcmp(filtertype, "scharr3")) + USE_FILTER(filter_scharr3); + if(!strcmp(filtertype, "sobel3")) + USE_FILTER(filter_sobel3); + if(!strcmp(filtertype, "prewitt5")) + USE_FILTER(filter_prewitt5); + if(!strcmp(filtertype, "sobel5")) + USE_FILTER(filter_sobel5); + + if(scale < 0) + { + if(filter) + hmap_to_nmap_local(nmap, image_width, image_height, -scale-1, offset, filter, filterw, filterh); + else + hmap_to_nmap(nmap, image_width, image_height, -scale-1, offset); + } else - nmap_to_hmap(nmap, refmap, image_width, image_height, scale, offset); + nmap_to_hmap(nmap, refmap, image_width, image_height, scale, offset, filter, filterw, filterh); + if(!Image_WriteTGABGRA(outfile, image_width, image_height, nmap)) { printf("Image_WriteTGABGRA failed\n");