Bayer转换算法

1、Bayer转换算法转/* raw.h */#ifndef _RAW_H_ #define _RAW_H_ #define GP_OK 1 typedef enum BAYER_TILE_RGGB = 0, BAYER_TILE_GRBG = 1, BAYER_TILE_BGGR = 2, BAYER_TILE_GBRG = 3, BAYER_TILE_RGGB_INTERLACED = 4, BAYER_TILE_GRBG_INTERLACED = 5, BAYER_TILE_BGGR_INTERLACED = 6, BAYER_TILE_GBRG_INTERLACED = 7, BayerT

2、ile; int gp_bayer_expand (unsigned char *input, int w, int h, unsigned char *output, BayerTile tile); int gp_bayer_decode (unsigned char *input, int w, int h, unsigned char *output, BayerTile tile); int gp_bayer_interpolate (unsigned char *image, int w, int h, BayerTile tile); #endif /* raw.c */#inc

3、lude raw.h static const int tile_colours84 = 0, 1, 1, 2, 1, 0, 2, 1, 2, 1, 1, 0, 1, 2, 0, 1, 0, 1, 1, 2, 1, 0, 2, 1, 2, 1, 1, 0, 1, 2, 0, 1; #define RED 0 #define GREEN 1 #define BLUE 2 static int gp_bayer_accrue (unsigned char *image, int w, int h, int x0, int y0, int x1, int y1, int x2, int y2, in

4、t x3, int y3, int colour); int gp_bayer_expand (unsigned char *input, int w, int h, unsigned char *output, BayerTile tile) int x, y, i; int colour, bayer; unsigned char *ptr = input; switch (tile) case BAYER_TILE_RGGB: case BAYER_TILE_GRBG: case BAYER_TILE_BGGR: case BAYER_TILE_GBRG: for (y = 0; y h

5、; +y) for (x = 0; x w; +x, +ptr) bayer = (x&1?0:1) + (y&1?0:2); colour = tile_colourstilebayer; i = (y * w + x) * 3; outputi+RED = 0; outputi+GREEN = 0; outputi+BLUE = 0; outputi+colour = *ptr; break; case BAYER_TILE_RGGB_INTERLACED: case BAYER_TILE_GRBG_INTERLACED: case BAYER_TILE_BGGR_INTERLACED:

6、case BAYER_TILE_GBRG_INTERLACED: for (y = 0; y h; +y, ptr+=w) for (x = 0; x 1:ptr(w1)+(x1); break; return (GP_OK); #define AD(x, y, w) (y)*(w)*3+3*(x) int gp_bayer_interpolate (unsigned char *image, int w, int h, BayerTile tile) int x, y, bayer; int p0, p1, p2, p3; int value, div ; switch (tile) def

7、ault: case BAYER_TILE_RGGB: case BAYER_TILE_RGGB_INTERLACED: p0 = 0; p1 = 1; p2 = 2; p3 = 3; break; case BAYER_TILE_GRBG: case BAYER_TILE_GRBG_INTERLACED: p0 = 1; p1 = 0; p2 = 3; p3 = 2; break; case BAYER_TILE_BGGR: case BAYER_TILE_BGGR_INTERLACED: p0 = 3; p1 = 2; p2 = 1; p3 = 0; break; case BAYER_T

8、ILE_GBRG: case BAYER_TILE_GBRG_INTERLACED: p0 = 2; p1 = 3; p2 = 0; p3 = 1; break; for (y = 0; y h; y+) for (x = 0; x w; x+) bayer = (x&1?0:1) + (y&1?0:2); if ( bayer = p0 ) /* red. green lrtb, blue diagonals */ imageAD(x,y,w)+GREEN = gp_bayer_accrue(image, w, h, x-1, y, x+1, y, x, y-1, x, y+1, GREEN

9、) ; imageAD(x,y,w)+BLUE = gp_bayer_accrue(image, w, h, x+1, y+1, x-1, y-1, x-1, y+1, x+1, y-1, BLUE) ; else if (bayer = p1) /* green. red lr, blue tb */ div = value = 0; if (x (w - 1) value += imageAD(x+1,y,w)+RED; div+; if (x) value += imageAD(x-1,y,w)+RED; div+; imageAD(x,y,w)+RED = value / div; d

10、iv = value = 0; if (y (h - 1) value += imageAD(x,y+1,w)+BLUE; div+; if (y) value += imageAD(x,y-1,w)+BLUE; div+; imageAD(x,y,w)+BLUE = value / div; else if ( bayer = p2 ) /* green. blue lr, red tb */ div = value = 0; if (x (w - 1) value += imageAD(x+1,y,w)+BLUE; div+; if (x) value += imageAD(x-1,y,w

11、)+BLUE; div+; imageAD(x,y,w)+BLUE = value / div; div = value = 0; if (y (h - 1) value += imageAD(x,y+1,w)+RED; div+; if (y) value += imageAD(x,y-1,w)+RED; div+; imageAD(x,y,w)+RED = value / div; else /* blue. green lrtb, red diagonals */ imageAD(x,y,w)+GREEN = gp_bayer_accrue (image, w, h, x-1, y, x

12、+1, y, x, y-1, x, y+1, GREEN) ; imageAD(x,y,w)+RED = gp_bayer_accrue (image, w, h, x+1, y+1, x-1, y-1, x-1, y+1, x+1, y-1, RED) ; return (GP_OK); static int gp_bayer_accrue (unsigned char *image, int w, int h, int x0, int y0, int x1, int y1, int x2, int y2, int x3, int y3, int colour) int x 4 ; int

13、y 4 ; int value 4 ; int above 4 ; int counter ; int sum_of_values; int average ; int i ; x0 = x0 ; x1 = x1 ; x2 = x2 ; x3 = x3 ; y0 = y0 ; y1 = y1 ; y2 = y2 ; y3 = y3 ; counter = sum_of_values = 0 ; if(colour = GREEN) for (i = 0 ; i = 0) & (xi = 0) & (yi 2*vdiff) return (value 3 + value 2)/2 ; if(vd

14、iff 2*hdiff) return (value 1 + value 0)/2 ; /* for blue and red */ counter = sum_of_values = 0 ; for (i = 0 ; i = 0) & (xi = 0) & (yi h) value i = imageAD(xi,yi,w) + colour ; sum_of_values += value i ; counter+ ; average = sum_of_values / counter ; if (counter 4) return average ; /* Less than four s

15、urrounding - just take average */ counter = 0 ; for (i = 0 ; i average ; if (abovei) counter+ ; /* Note: counter = 0 indicates all values the same */ if (counter = 2) | (counter = 0) return average ; sum_of_values = 0 ; for (i = 0 ; i 4 ; i+) if (counter = 3) = abovei) sum_of_values += valuei ; retu

16、rn sum_of_values / 3 ; int gp_bayer_decode (unsigned char *input, int w, int h, unsigned char *output, BayerTile tile) gp_bayer_expand (input, w, h, output, tile); gp_bayer_interpolate (output, w, h, tile); return (GP_OK); Bayer图像处理Bayer是相机内部的原始图片, 一般后缀名为.raw. 很多软件都可以查看, 比如PS.我们相机拍照下来存储在存储卡上的.jpeg或其

17、它格式的图片, 都是从.raw格式转化过来的. .raw格式内部的存储方式有多种, 但不管如何, 都是前两行的排列不同. 其格式可能如下:G R G R G R G RB G B G B G B GG R G R G R G RB G B G B G B G横为2的倍数, 竖为4的倍数, 它们构成了分辨率. 如, 上面则代表了 8 * 4 分辨率的Bayer图.我们要知道的是, G = 2 * R 及 G = 2 * B, 即绿色值为红色值或蓝色值的两倍, 因为人眼对绿色更敏感, 所以绿色的分量更重.下面说一下从bayer转换成rgb图的算法, RGB图, 即为三色图, 一个像素点就由RGB三

18、种颜色构成的混合色, 而bayer图一个像素就只有一个颜色, 或R或G或B. 因为bayer一个像素点只有一种颜色, 需要借助这个像素点周围的颜色对它进行插值(填充)另外的两种颜色, 它本身的颜色就不用插了. 一般的算法是:对于插入R和B, Rx = ( R1 + R2 ) / 2; 或-取上边和下边的平均值, 或是左边和右边的平均值Rx = ( R1 + R2 + R3 + R4 ) / 4;-取四个边的平均值B同理. 如:G B GR G RG B G对于中间的G, 它缺少 R和B, 用上下和左右的平均值进行求值.对于B G BG R GB G B这个图呢, 中间点R, 缺少G和B, G暂时没讨论, 那么 B, 就是从R的四个B角进行求平均值.=如果插入G, 稍有些复杂.不过一般的算法与R和B一样, 复杂的算法, 其复杂程度也提升一倍, 不过精度更高, 如果对于视频监测系统来说, 精度相对来说不必要求太高, 用R或B的解法即可. 下面说复杂的:对于图:R1G1R4 G4 R G2 R2G3R3对于中间点R, 它需要插