/****************************************************************************** Copyright (C) Michael Still 2002 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. ******************************************************************************/ #include #include #include char *readimage(char *filename, unsigned long *width, unsigned long *height, int *bitdepth, int *channels); char *inflateraster(char *input, unsigned long width, unsigned long height, int bitdepth, int targetbitdepth, int channels, int targetchannels); int main (int argc, char *argv[]) { FILE *image; unsigned int i; unsigned long gnux, gnuy; png_uint_32 rowbytes; png_structp png; png_infop info; png_bytepp row_pointers = NULL; plot_state *graph; char *raster, *gnu, *newgnu, *input, *newinput; int gnubitdepth, gnuchannels; if((graph = plot_newplot(900, 800)) == NULL){ fprintf(stderr, "Could not allocate a new plot\n"); exit(1); } // Get another raster to use for testing if((gnu = readimage("gnu.png", &gnux, &gnuy, &gnubitdepth, &gnuchannels)) == -1){ fprintf(stderr, "Cannot read the gnu.png test image\n"); exit(42); } printf("Gnu image is %d by %d @ %d channels and %d bits per channel\n", gnux, gnuy, gnuchannels, gnubitdepth); if((newgnu = inflateraster(gnu, gnux, gnuy, gnubitdepth, 8, gnuchannels, 3)) == -1){ fprintf(stderr, "Cannot inflate the raster of the gnu image\n"); exit(42); } // Shrink plot_overlayraster(graph, newgnu, 10, 10, 90, 90, gnux, gnuy, 0); plot_setlinecolor(graph, 255, 0, 0); plot_rectangle(graph, 10, 10, 90, 90); plot_strokeline(graph); plot_endline(graph); // Expand plot_overlayraster(graph, newgnu, 100, 100, 900, 900, gnux, gnuy, 0); plot_setlinecolor(graph, 255, 0, 0); plot_rectangle(graph, 100, 100, 900, 900); plot_strokeline(graph); plot_endline(graph); // Get another raster to use for testing -- this time increasing samples as well if((input = readimage("input.png", &gnux, &gnuy, &gnubitdepth, &gnuchannels)) == -1){ fprintf(stderr, "Cannot read the gnu.png test image\n"); exit(42); } printf("Input image is %d by %d @ %d channels and %d bits per channel\n", gnux, gnuy, gnuchannels, gnubitdepth); // This held me up for a little while -- the image is packed to 8 bits per // pixel by the read, but is actually only using the values 0 and 1, which // are too close to tell apart in 24 bit color land... for(i = 0; i < gnux * gnuy; i++){ if(input[i] == 1) input[i] = 255; } if((newinput = inflateraster(input, gnux, gnuy, 8, 8, gnuchannels, 3)) == -1){ fprintf(stderr, "Cannot inflate the raster image\n"); exit(42); } plot_overlayraster(graph, newinput, 100, 10, 800, 700, gnux, gnuy, 1); plot_setlinecolor(graph, 255, 0, 0); plot_rectangle(graph, 100, 10, 800, 700); plot_strokeline(graph); plot_endline(graph); // A red line from 10, 10 to 20, 10 plot_setlinecolor(graph, 255, 0, 0); plot_setlinestart(graph, 10, 10); plot_addlinesegment(graph, 20, 10); plot_strokeline(graph); plot_endline(graph); plot_setlinecolor(graph, 0, 255, 0); plot_rectangle(graph, 20, 20, 30, 40); plot_strokeline(graph); plot_endline(graph); plot_setlinecolor(graph, 0, 0, 255); plot_setlinestart(graph, 10, 10); plot_addlinesegment(graph, 20, 20); plot_strokeline(graph); plot_endline(graph); plot_setlinestart(graph, 20, 10); plot_addlinesegment(graph, 30, 30); plot_strokeline(graph); plot_endline(graph); plot_setlinecolor(graph, 255, 0, 0); plot_setlinestart(graph, 30, 30); plot_addlinesegment(graph, 50, 40); plot_strokeline(graph); plot_endline(graph); plot_setlinestart(graph, 30, 30); plot_addlinesegment(graph, 25, 25); plot_strokeline(graph); plot_endline(graph); plot_setlinestart(graph, 98, 100); plot_addlinesegment(graph, 102, 100); plot_strokeline(graph); plot_endline(graph); plot_setlinestart(graph, 100, 98); plot_addlinesegment(graph, 100, 102); plot_strokeline(graph); plot_endline(graph); plot_setlinecolor(graph, 0, 0, 0); plot_circle(graph, 100, 100, 50); plot_strokeline(graph); plot_endline(graph); raster = plot_getraster(graph); if((image = fopen("output.png", "wb")) == NULL){ fprintf(stderr, "Could not open the output image\n"); exit(42); } // Get ready for writing if ((png = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL)) == NULL){ fprintf(stderr, "Could not create write structure for PNG (out of memory?)"); exit(42); } // Get ready to specify important stuff about the image if ((info = png_create_info_struct (png)) == NULL){ fprintf(stderr, "Could not create PNG info structure for writing (out of memory?)"); exit(42); } if (setjmp (png_jmpbuf (png))){ fprintf(stderr, "Could not set the PNG jump value for writing"); exit(42); } // This is needed before IO will work (unless you define callbacks) png_init_io(png, image); // Define important stuff about the image info->channels = 3; info->pixel_depth = 24; png_set_IHDR (png, info, 900, 800, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); png_write_info (png, info); // Write the image out if((row_pointers = malloc (800 * sizeof (png_bytep))) == NULL){ fprintf(stderr, "Could not allocate memory\n"); exit(42); } for(i = 0; i < 800; i++){ row_pointers[i] = raster + (i * 900 * 3); } png_write_image (png, row_pointers); // Cleanup png_write_end (png, info); png_destroy_write_struct (&png, &info); fclose(image); }