求大神帮我看一下对比度调整的算法。在24位的图像中每个像素占3字节，每行是4字节吗？

Question

//对比度调整
private: System::Void hScrollBar5_Scroll(System::Object^  sender, System::Windows::Forms::ScrollEventArgs^  e)
   {
    int cdegree;
    cdegree = hScrollBar5->Value;
    label13->Text = cdegree.ToString();
    if (cdegree < -100) cdegree = -100;
             if (cdegree > 100) cdegree = 100;
             double pixel = 0;
             double contrast = (100.0 + cdegree) / 100.0; 
             contrast *= contrast;
             int w = bitmap->Width;
             int h = bitmap->Height;
             //锁定位图对象至内存，存为24位
       Rectangle rt = Rectangle(0,0,w,h);
       System::Drawing::Imaging::BitmapData^ srcData = bitmap->LockBits(rt,ImageLockMode::ReadWrite,bitmap->PixelFormat);
       IntPtr p = srcData->Scan0;       //获取第一行开头的地址
       //用一个数组来存储位图的字节
       int bytes = Math::Abs(srcData->Stride) * h;
             array<Byte>^rgbValues = gcnew array<Byte>(bytes);
             //把RGB的值都复制到该数组中
             System::Runtime::InteropServices::Marshal::Copy( p, rgbValues, 0, bytes );
            // 处理指定位置像素的对比度
             for (int counter = 0; counter<rgbValues->Length; counter=counter+3)
              for(int i=counter;i<=counter+2;i++)
     {
                    pixel = ((rgbValues[i] / 255.0- 0.5) * contrast + 0.5) * 255;
                    if (pixel < 0) pixel = 0;
                    if (pixel > 255) pixel = 255;
                    rgbValues[i] = (Byte)pixel;
 
              }
              //把新的RGB值复制回位图中
           System::Runtime::InteropServices::Marshal::Copy( rgbValues, 0, p, bytes );
     //解锁位图
           bitmap->UnlockBits(srcData);
     pictureBox1->Image = bitmap;
   }

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新手上路，大神指点！

Answer 1

关于Bitmap位图的对齐可以参考我的代码里输出Bitmap的那的一部分http://download.csdn.net/detail/Vonger/1699976

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0xDEADBEEF

Answer 2

您好，

首先，非常感谢您的积极参与。

根据您的描述，您的问题没有固定的答案。所以我认为将这个帖子的类型改为“常规讨论”会更好一些。

谢谢您的理解。

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Damon Zheng [MSFT]
MSDN Community Support | Feedback to us

Answer 3

嗯，我已经解决了，谢谢~这个论坛真不错！

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新手上路，大神指点！