opencl-圖像對象鉗到邊

Question

我有兩個不同的內核sobel操作符。 一個使用緩衝區對象，另一個使用圖像對象。

在我看來，這兩個內核應該做出相同的結果，但他們不是。

使用（鉗位到邊）

是有問題這兩個代碼手柄邊緣？

用緩衝對象

__kernel空隙sobel_filter（__全球UCHAR * ucGRAY，__global浮子*索貝爾，__global浮* grad_max，INT im_width，INT im_height） { FLOAT2 XT; int i = get_global_id（0）; int j = get_global_id（1）;

int ii_p, jj_p, ii_n, jj_n; // ii_n,jj_n = (i,j)-1 ii_p,jj_p = (i,j)+1 


    if (i == 0) 
     ii_n = i; 
    else if (i == im_width - 1) 
     ii_p = i; 
    else 
    { 
     ii_n = i - 1; 
     ii_p = i + 1; 
    } 
    if (j == 0) 
     jj_n = i; 
    else if (j == im_height - 1) 
     jj_p = j; 
    else 
    { 
     jj_n = j - 1; 
     jj_p = j + 1; 
    } 


    xt.x = (float)(ucGRAY[(jj_n)* im_width + (ii_p)] // 3 
       + ucGRAY[j * im_width + (ii_p)] * 2 //6 
       + ucGRAY[(jj_p) * im_width + (ii_p)] //9 

       - ucGRAY[(jj_n)* im_width + (ii_n)] //1 
       - ucGRAY[j * im_width + (ii_n)] * 2 //4 
       - ucGRAY[(jj_p)* im_width + (ii_n)])/1020; //7 

    xt.y =(float)( ucGRAY[(jj_p)* im_width + (ii_n)] //7 
       +ucGRAY[(jj_p)* im_width + (i)] * 2 //8 
       +ucGRAY[(jj_p)* im_width + (ii_p)] //9 

       - ucGRAY[(jj_n)* im_width + (ii_n)] //1 
       - ucGRAY[(jj_n)* im_width + (i)] * 2 //2 
       - ucGRAY[(jj_n)* im_width + (ii_p)])/1020; //3 


    sobel[j * im_height + i] = length(xt); 

    AtomicMax(grad_max, sobel[j * im_width + i]); 
} 

與圖像對象

const sampler_t smp = CLK_NORMALIZED_COORDS_FALSE | //Natural coordinates 
         CLK_ADDRESS_CLAMP_TO_EDGE | //Clamp to edge 
         CLK_FILTER_NEAREST; //Don't interpolate 

__kernel void sobel_filter_image(read_only image2d_t ucGRAY,__global float *sobel,__global float *grad_max,int Width, int Height) 

{ 

    int2 coord = (int2)(get_global_id(0), get_global_id(1)); 

    float2 xt; 
    float temp; 

     uchar val5=read_imageui(ucGRAY, smp, (int2)(coord.x,coord.y)).x; 


     uchar val1=read_imageui(ucGRAY, smp, (int2)(coord.x-1,coord.y-1)).x; 
     uchar val2=read_imageui(ucGRAY, smp, (int2)(coord.x,coord.y-1)).x; 
     uchar val3=read_imageui(ucGRAY, smp, (int2)(coord.x+1,coord.y-1)).x; 


     uchar val4=read_imageui(ucGRAY, smp, (int2)(coord.x-1,coord.y)).x;  
     uchar val6=read_imageui(ucGRAY, smp, (int2)(coord.x+1,coord.y)).x; 

     uchar val7=read_imageui(ucGRAY, smp, (int2)(coord.x-1,coord.y+1)).x; 
     uchar val8=read_imageui(ucGRAY, smp, (int2)(coord.x,coord.y+1)).x; 
     uchar val9=read_imageui(ucGRAY, smp, (int2)(coord.x+1,coord.y+1)).x; 


     xt.x = (float)(val3 + (val6 * 2) + val9 
        - val1 - (val4 * 2) - val7)/1020; 
     xt.y = (float)(val7 + (val8 * 2) + val9 
        - val1 - (val2 * 2) - val3)/1020; 
    sobel[coord.y * Width + coord.x] = length(xt);// G=sqrt(Gy^2+Gx^2) 

    AtomicMax(grad_max,sobel[coord.y * Width + coord.x]); 


} 

Answer 1

在你的緩衝版本，你有這樣的：

if (j == 0) 
    jj_n = i; 

據推測，應該是：

if (j == 0) 
    jj_n = j;