img2twit: reinstate old interpolation tuning for final picture quality.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@3540 92316355-f0b4-4df1-b90c-862c8a59935f

examples/img2twit.cpp

@@ -749,8 +749,9 @@ static void render(pipi_image_t *dst, int rx, int ry, int rw, int rh)
                 //float k = pow((*it).second, (1.0f + fs));
 
                 // Try to attenuate peak artifacts
-                //k /= (0.1 * (RANGE_X * RANGE_X + RANGE_Y * RANGE_Y)
-                //       + (myx - fx) * (myx - fx) + (myy - fy) * (myy - fy));
+                k *= pow(((myx - fx) * (myx - fx) + (myy - fy) * (myy - fy)
+                          + 0.01) / (RANGE_X * RANGE_X + RANGE_Y * RANGE_Y),
+                          -0.5);
 
                 // Cute circles
                 //k = 1.0 / (0.015 * (RANGE_X * RANGE_X + RANGE_Y * RANGE_Y)