Changeset 2681Tweet

Timestamp:

Aug 8, 2008, 8:11:24 PM (15 years ago)

Author:

Sam Hocevar

Message:

• blur.c: implement box blur; currently runs in O(n) but we could make it O(1) trivially.

Location:

libpipi/trunk/pipi

Files:

• filter/blur.c (modified) (1 diff)
• pipi.h (modified) (1 diff)

libpipi/trunk/pipi/filter/blur.c

@@ -86 +86 @@
 }
 
+/* FIXME: box blur would be incredibly faster using an accumulator instead
+ * of a convolution filter... */
+pipi_image_t *pipi_box_blur(pipi_image_t *src, int size)
+{
+    return pipi_box_blur_ext(src, size, size);
+}
+
+pipi_image_t *pipi_box_blur_ext(pipi_image_t *src, int m, int n)
+{
+    pipi_image_t *ret;
+    double *kernel;
+    int i;
+
+    kernel = malloc(m * n * sizeof(double));
+    for(i = 0; i < m * n; i++)
+        kernel[i] = 1. / (m * n);
+
+    ret = pipi_convolution(src, m, n, kernel);
+
+    free(kernel);
+
+    return ret;
+}
+

libpipi/trunk/pipi/pipi.h

@@ -82 +82 @@
 extern pipi_image_t *pipi_gaussian_blur_ext(pipi_image_t *,
                                             float, float, float, float);
+extern pipi_image_t *pipi_box_blur(pipi_image_t *, int);
+extern pipi_image_t *pipi_box_blur_ext(pipi_image_t *, int, int);
 extern pipi_image_t *pipi_autocontrast(pipi_image_t *);