C++中的Box滤波算法

我正在使用框过滤算法来进行RGB图像模糊。但结果真的很糟糕。我根本认不出原来的图像。图像的数据存储在阵列Data[Width*Height*3]中，顺序为BGRBGRBGR。。。kernel是一个9x9的盒子。

这是我的盒子过滤功能：

void MyImage::BoxFiltering(vector<int> kernel){
char *temp = new char[Width * Height * 3];
int denominator = 0;
int indexOffset;
int red = 0, blue = 0, green = 0;
int indices[] = {-(Width + 1), -Width, -(Width - 1),
                 - 1,          0,      1,
                 Width - 1,    Width,  Width + 1};
for(int i = 0; i < kernel.size(); ++i){
    denominator += kernel[i];
}

if(denominator == 0)
    denominator = 1;
//Copy Data
for(int i = 0; i < Width * Height * 3; ++i){
    temp[i] = Data[i];
}
for(int i = 1; i < Height - 1; ++i){
    for(int j = 1; j < Width - 1; ++j){
        //Get Pixel Index
        indexOffset = getIndex(j, i);
        for(int k = 0; k < kernel.size(); ++k){
            blue    += Data[3 * (indexOffset + indices[k])] * kernel[k];
            green   += Data[3 * (indexOffset + indices[k]) + 1] * kernel[k];
            red     += Data[3 * (indexOffset + indices[k]) + 2] * kernel[k];
        }
        temp[3 * indexOffset] = static_cast<char>(blue / denominator);
        temp[3 * indexOffset + 1] = static_cast<char>(green / denominator);
        temp[3 * indexOffset + 2] = static_cast<char>(red / denominator);
    }
}
for(int i = 0; i < Width * Height * 3; ++i){
    Data[i] = temp[i];
}
delete [] temp;
}

有人能帮我弄清楚我的实现出了什么问题吗？谢谢