+#include <images/image-walk.h>
+
+/* Grayscale <-> YCbCr */
+
+#define IMAGE_WALK_PREFIX(x) walk_##x
+#define IMAGE_WALK_FUNC_NAME image_conv_gray_1_to_ycbcr_n
+#define IMAGE_WALK_DOUBLE
+#define IMAGE_WALK_SEC_COL_STEP 1
+#define IMAGE_WALK_UNROLL 4
+#define IMAGE_WALK_DO_STEP do{ walk_pos[0] = walk_sec_pos[0]; walk_pos[1] = walk_pos[2] = 0; }while(0)
+#include <images/image-walk.h>
+
+#define IMAGE_WALK_PREFIX(x) walk_##x
+#define IMAGE_WALK_FUNC_NAME image_conv_ycbcr_n_to_gray_1
+#define IMAGE_WALK_DOUBLE
+#define IMAGE_WALK_COL_STEP 1
+#define IMAGE_WALK_UNROLL 4
+#define IMAGE_WALK_DO_STEP do{ walk_pos[0] = walk_sec_pos[0]; }while(0)
+#include <images/image-walk.h>