+// finds empty borders and return non-empty area of image:
+static wxImage CutEmptyBorders(const wxImage& img)
+{
+ unsigned char mr = img.GetMaskRed(),
+ mg = img.GetMaskGreen(),
+ mb = img.GetMaskBlue();
+ unsigned char *dt = img.GetData(), *dttmp;
+ unsigned w = img.GetWidth(), h = img.GetHeight();
+
+ unsigned top, bottom, left, right, i;
+ bool empt;
+
+#define MK_DTTMP(x,y) dttmp = dt + ((x + y * w) * 3)
+#define NOEMPTY_PIX(empt) if (dttmp[0] != mr || dttmp[1] != mg || dttmp[2] != mb) {empt = FALSE; break;}
+
+ for (empt = TRUE, top = 0; empt && top < h; top++)
+ {
+ MK_DTTMP(0, top);
+ for (i = 0; i < w; i++, dttmp+=3)
+ NOEMPTY_PIX(empt)
+ }
+ for (empt = TRUE, bottom = h-1; empt && bottom > top; bottom--)
+ {
+ MK_DTTMP(0, bottom);
+ for (i = 0; i < w; i++, dttmp+=3)
+ NOEMPTY_PIX(empt)
+ }
+ for (empt = TRUE, left = 0; empt && left < w; left++)
+ {
+ MK_DTTMP(left, 0);
+ for (i = 0; i < h; i++, dttmp+=3*w)
+ NOEMPTY_PIX(empt)
+ }
+ for (empt = TRUE, right = w-1; empt && right > left; right--)
+ {
+ MK_DTTMP(right, 0);
+ for (i = 0; i < h; i++, dttmp+=3*w)
+ NOEMPTY_PIX(empt)
+ }
+ top--, left--, bottom++, right++;
+
+ return img.GetSubImage(wxRect(left, top, right - left + 1, bottom - top + 1));
+}
+
+
+