diff --git a/src/main.c b/src/main.c
index 32a0f47..72ebd3b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -55,12 +55,12 @@ int main(int argc, char *argv[])
    finish = clock();
    printf("rgb2yuv_tables64: %.3f sec\n", (float) (finish - start) / CLOCKS_PER_SEC);

-#ifdef PRINT_PIXELS
-   for (i = 0; i < 4 * PIXELS_COUNT; i++)
+
+   for (i = 0; i < 27; i++)
    {
        printf("%d: %d %d %d %d\n", i, pixels_wiki[i], pixels_novel_ch[i], pixels_tables[i], pixels_tables64[i]);
    }
-#endif
+

    return 0;
 }
diff --git a/src/rgb2yuv_tables64.c b/src/rgb2yuv_tables64.c
index f30be2d..c49d641 100644
--- a/src/rgb2yuv_tables64.c
+++ b/src/rgb2yuv_tables64.c
@@ -6,15 +6,15 @@
  */

 #include "rgb2yuv.h"
-
+#include <stdio.h>
 static int64_t t_r3[256], t_g3[256], t_b3[256];

 void rgb2yuv_tables64_init(void)
 {
    int i, j;
-   int k_r[] = {  66, -38, 112 };
-   int k_g[] = { 129, -74, -94 };
-   int k_b[] = {  25, 112, -18 };
+   int k_r[] = {  47, -26, 112 };
+   int k_g[] = { 157, -87, -102 };
+   int k_b[] = {  16, 112, -10 };


    for (i = 0; i <= 255; i++)
@@ -36,9 +36,7 @@ void rgb2yuv_tables64(uint8_t *pixels, int count)
 {
    int t;
    uint8_t r, g, b;
-   int64_t c1 = (128LL << 32) + (128 << 16) + 128 +
-           (16LL << 40) + (128LL << 24) + (128 << 8);
-
+   int64_t c1 = ((uint64_t) 4096 << 32) + (32768 << 16) + (32768);
    for (t = 0; t < count * 4; t += 4)
    {
        r = pixels[t + 1];
@@ -51,4 +49,4 @@ void rgb2yuv_tables64(uint8_t *pixels, int count)
        pixels[t + 2] = x3 >> 24;
        pixels[t + 3] = x3 >> 8;
    }
-}
+}
diff --git a/src/rgb2yuv_wiki.c b/src/rgb2yuv_wiki.c
index d1d82f2..b5c406f 100644
--- a/src/rgb2yuv_wiki.c
+++ b/src/rgb2yuv_wiki.c
@@ -6,24 +6,28 @@

 #include "rgb2yuv.h"

-#define RGB2Y(R, G, B) (0.299 * R + 0.587 * G + 0.114 * B)
-#define RGB2U(R, G, B) (-0.14713 * R - 0.28886 * G + 0.436 * B + 128)
-#define RGB2V(R, G, B) (0.615 * R - 0.51499 * G - 0.10001 * B + 128)
-
+#define RGB2Y(R, G, B) (  47 * (R) + 157 * (G) +  16 * (B) + 4096) >> 8
+#define RGB2U(R, G, B) ( -26 * (R) +  -87 * (G) + 112 * (B) + 32768) >> 8
+#define RGB2V(R, G, B) ( 112 * (R) +  -102 * (G) +  -10 * (B) + 32768) >> 8
 void rgb2yuv_wiki(uint8_t *pixels, int count)
 {
-   int t;
-   int r, g, b;
-
-   for (t = 0; t < count * 4; t += 4)
-   {
-       r = pixels[t + 1];
-       g = pixels[t + 2];
-       b = pixels[t + 3];
-       pixels[t + 1] = RGB2Y(r,g,b);
-       pixels[t + 2] = RGB2U(r,g,b);
-       pixels[t + 3] = RGB2V(r,g,b);
-   }
+        int i, t;
+        int y, u, v;
+        int r, g, b;
+        uint8_t *p = pixels;

+        for (i = 0; i < count; i++)
+        {
+                t = i * 4;
+                y = t + 1;
+                u = t + 2;
+                v = t + 3;
+                r = p[y];
+                g = p[u];
+                b = p[v];
+                p[y] = RGB2Y(r,g,b);
+                p[u] = RGB2U(r,g,b);
+                p[v] = RGB2V(r,g,b);
+        }
 }