pcf.c

   1 #include <Python.h>
   2
   3 static PyObject* py_edge(PyObject* self, PyObject* args)
   4 {
   5         const unsigned char *image;
   6         int x;
   7         int y;
   8         int size;
   9
  10         int i;
  11         int j;
  12         int sum;
  13
  14         unsigned char *n_image;
  15         PyObject *result;
  16
  17         if (!PyArg_ParseTuple(args, "(ii)s#", &x, &y, &image, &size)) return NULL;
  18
  19         n_image = (char*) malloc(size);
  20         for (i=0; i < 2 * x; i++) {
  21                 n_image[i] = 0;
  22                 n_image[(y - 2) * x + i] = 0;
  23         }
  24         for (i=0; i < y; i++) {
  25                 n_image[x * i] = 0;
  26                 n_image[x * i + 1] = 0;
  27                 n_image[x * i + x - 2] = 0;
  28                 n_image[x * i + x - 1] = 0;
  29         }
  30
  31
  32
  33         for (i=2; i < x - 2; i++) {
  34                 for (j=2; j < y - 2; j++) {
  35                         sum = image[x * j + i - 2] + image[x * j + i - 1] + image[x * j + i + 1] + image[x * j + i + 2] +
  36                                 image[x * (j - 2) + i - 2] + image[x * (j - 2) + i - 1] + image[x * (j - 2) + i] +
  37                                 image[x * (j - 2) + i + 1] + image[x * (j - 2) + i + 2] +
  38                                 image[x * (j - 1) + i - 2] + image[x * (j - 1) + i - 1] + image[x * (j - 1) + i] +
  39                                 image[x * (j - 1) + i + 1] + image[x * (j - 1) + i + 2] +
  40                                 image[x * (j + 2) + i - 2] + image[x * (j + 2) + i - 1] + image[x * (j + 2) + i] +
  41                                 image[x * (j + 2) + i + 1] + image[x * (j + 2) + i + 2] +
  42                                 image[x * (j + 1) + i - 2] + image[x * (j + 1) + i - 1] + image[x * (j + 1) + i] +
  43                                 image[x * (j + 1) + i + 1] + image[x * (j + 1) + i + 2]
  44                                 - (25 * image[x * j + i]);
  45                         if (sum < 0) sum = 0;
  46                         if (sum > 255) sum = 255;
  47                         n_image[x * j + i] = sum;
  48                 }
  49         }
  50
  51
  52
  53         result = Py_BuildValue("s#", n_image, size);
  54         free(n_image);
  55         return result;
  56 }
  57
  58
  59 static PyMethodDef myModule_methods[] = {
  60         {"edge", py_edge, METH_VARARGS},
  61         {NULL, NULL}
  62 };
  63
  64 void initpcf()
  65 {
  66                 (void) Py_InitModule("pcf", myModule_methods);
  67 }