convolution.rs

#pragma version(1)
#pragma rs java_package_name(com.ap.wificam)
#pragma rs_fp_imprecise

rs_allocation input;
rs_allocation mask;
rs_allocation histogram_r;
rs_allocation histogram_g;
rs_allocation histogram_b;


uint32_t width;
uint32_t height;
int32_t *laplaceMax;
int32_t *laplaceSum;

void root(uchar4* out, uint32_t x, uint32_t y) {
    const int size_x = 5;
    const int size_y = 5;
    const int offset_x = size_x/2;
    const int offset_y = size_y/2;

    //Histogram Accumulation
    int4 pixel = 0.0f;
    pixel = convert_int4(rsGetElementAt_uchar4(input, x, y));
    int bucket_r = rsGetElementAt_int(histogram_r, pixel.x, 0);
    int bucket_g = rsGetElementAt_int(histogram_g, pixel.y, 0);
    int bucket_b = rsGetElementAt_int(histogram_b, pixel.z, 0);
    rsSetElementAt_int(histogram_r, bucket_r+1, pixel.x, 0);
    rsSetElementAt_int(histogram_g, bucket_g+1, pixel.y, 0);
    rsSetElementAt_int(histogram_b, bucket_b+1, pixel.z, 0);

    //Laplace Convolution
    int4 sum = 0.0f;
    for (int yi = 0; yi < size_y; ++yi) {
        int yc = y - offset_y + yi;
        yc = min(max(yc, 0), (int)height-1);
        for (int xi = 0; xi < size_x; ++xi) {
            int xc = x - offset_x + xi;
            xc = min(max(xc, 0), (int)width-1);
            sum += convert_int4(rsGetElementAt_uchar4(input, xc, yc)) *
                           rsGetElementAt_int(mask, xi, yi);
        }
    }

    int laplaceValue = (sum.x + sum.y + sum.z)/3;

    //Calculate maximum Laplace and Laplace Sum
    if(laplaceValue > *laplaceMax){
         *laplaceMax = laplaceValue;
    }

    //normalize the laplace image values
    sum = min(sum, 255);
    sum = max(sum, 0);
    sum.w = 255;

    int laplaceValueNorm = (sum.x + sum.y + sum.z)/3;

    if((laplaceValueNorm > 128))
        *laplaceSum = *laplaceSum +1;

    if((x == width-1) && (y == height-1)){
        rsDebug("RenderScript.convolution.rs.sum", *laplaceSum);
        rsDebug("RenderScript.convolution.rs.max", *laplaceMax);
    }
    if((x == 500) && (y == 400)){
        rsDebug("RenderScript.convolution.rs.23 histogram.x at value 50", rsGetElementAt_int(histogram_g, 50, 0));
    }

    *out = convert_uchar4(sum);
}