Question

我正在编写一个程序，其中我在3D数组中有一个灰度图像：

    FILE *file;
    const int BytesPerPixel = 1;
    const int Size = 512;
    fread(Imagedata, sizeof(unsigned char), Size*Size*BytesPerPixel, file);
    fclose(file);

我想用零填充此图像，使得图像尺寸在每一侧都包含一个像素/行/列。这是我在main（）中编写的代码：

    const int padSize = 1;
    const int newLength = Size + (2 * padSize), newBreadth = Size + (2 * padSize);

    unsigned char*** paddedImage = padImageWithZeros(Imagedata, newLength, newBreadth, BytesPerPixel, padSize);

函数def位于我的Header文件中，该文件已包含在source.cpp中：

    unsigned char*** initializeImage(const int length, const int breadth, const int channels)
    {

        unsigned char*** newImage = new unsigned char**[channels];
        for (int i = 0; i < channels ; ++i)
        {
            newImage[i] = new unsigned char*[length];

            for (int j = 0; j < length; ++j)
            {
                    newImage[i][j] = new unsigned char[breadth];

                for (int k = 0; k < breadth; ++k)
                {
                    newImage[j][k][i] = (unsigned char)0;
                }
            }
        }

        return newImage;
    }



    unsigned char*** padImageWithZeros(unsigned char Imagedata[512][512][1],const int newLength,const int newBreadth, const int BytesPerPixel, const int padSize)
    {
        //Initializing a 3 channel padded Image
        unsigned char*** paddedImage = initializeImage(newLength, newBreadth, BytesPerPixel);


       //Storing the original image in the padded image
       for (int channel = 0; channel < BytesPerPixel; channel++)
       {
            cout << "Channel = " << channel << endl;
            for (int i = padSize; i < newLength; i++)
            {
                for (int j = padSize; j < newBreadth ; j++)
                {
                    cout << paddedImage[i][j][channel] << endl;
                    cout << "Yes" << endl;
                    paddedImage[i][j][channel] = Imagedata[i - padSize][j - padSize][channel];
                }
            }
        }

    return paddedImage;
    }

然而，在我检查刚刚初始化后删除的paddedImage矩阵后，它看起来像这样：

enter image description here

并在Visual Studio中运行代码会在

处出现访问冲突错误

    paddedImage[i][j][channel] = Imagedata[i - padSize][j - padSize][channel];

我有一种感觉我没有正确初始化paddedImage，但我不确定是什么问题。请帮忙。

编辑：更新的代码：函数调用main（）：

    const int padSize = 1;
    const int newLength = Size + (2 * padSize), newBreadth = Size + (2 * padSize);

    unsigned char*** paddedImage = padImageWithZeros(Imagedata, newLength, newBreadth, BytesPerPixel, padSize);

标题中的函数定义。 H：

    unsigned char*** initializeImage(const int length, const int breadth, const int channels)
    {
        unsigned char*** newImage = new unsigned char**[length];
        for (int i = 0; i < length; ++i)
        {
             newImage[i] = new unsigned char*[breadth];

             for (int j = 0; j < breadth; ++j)
             {
                  newImage[i][j] = new unsigned char[channels];

                  for (int k = 0; k < channels; ++k)
                  {
                      newImage[i][j][k] = (unsigned char)0;
                  }
              }
          }

           return newImage;
    }

    unsigned char*** padImageWithZeros(unsigned char Imagedata[512][512][1], const int newLength, const int newBreadth, const int BytesPerPixel, const int padSize)
    {
        //Initializing a 3 channel padded Image
        unsigned char*** paddedImage = initializeImage(newLength, newBreadth, BytesPerPixel);


       //Storing the original image in the padded image
       for (int channel = 0; channel < BytesPerPixel; channel++)
       {
           cout << "Channel = " << channel << endl;
           for (int i = padSize; i < newLength - padSize; i++)
       {
            for (int j = padSize; j < newBreadth - padSize; j++)
            {
                cout << paddedImage[i][j][channel] << endl;
                cout << "Yes" << endl;
                paddedImage[i][j][channel] = Imagedata[i - padSize][j - padSize][channel];
            }
        }
    }

    return paddedImage;
 }

输出： enter image description here enter image description here

Answer 1

这里有2个错误：

initializeImage函数，正如@ rafix07已经指出的那样。您需要image[channel][lenght]breadth]时正在初始化image[lenght][breadth][channel]（请参阅他对该功能所需修补程序的回答）
复制图像的循环使用了错误的范围。

你应该循环使用：

//Storing the original image in the padded image
for (int channel = 0; channel < BytesPerPixel; channel++)
{
     cout << "Channel = " << channel << endl;
     for (int i = padSize; i < newLength - padSize; i++)
     {
         for (int j = padSize; j < newBreadth - padSize; j++)
         {
             cout << paddedImage[i][j][channel] << endl;
             cout << "Yes" << endl;
             paddedImage[i][j][channel] = Imagedata[i - padSize][j - padSize][channel];
         }
     }
 }

请查看for循环终止条件。在您的解决方案中，您正在复制原始图片中的newLength-padSize元素，而您需要复制newLength-(2*padSize)。

我补充一点，处理图像的方式不是缓存友好的。它至少应为image[column][row][channels]。通过分配大小为length * breadth * channels的单维数组，然后使用某个成员函数来检索所需的像素或颜色组件（如getColor(x,y,channel)或setColor(newValue,x,y,channel)），可以提供另一项巨大的改进。单维数组将为您提供进一步优化的简便方法（例如使用指针）

Answer 2

我发现了问题。正如@Stefano Buro建议的那样，你必须将图像输出为一维数组，而不是我正在做的3D数组。

无法解决动态初始化2D阵列的问题

2 个答案: