A quick solution is to modify the image.c file to print out the bounding box information:
...
if(bot > im.h-1) bot = im.h-1;
// Print bounding box values
printf("Bounding Box: Left=%d, Top=%d, Right=%d, Bottom=%d\n", left, top, right, bot);
draw_box_width(im, left, top, right, bot, width, red, green, blue);
...