BCB实现BMP图片的RGB分解

曾经终败给现在 2022-05-14 01:10 209阅读 0赞

1、打开BMP图片文件，在Image控件中显示；

![None.gif][]  if (dlgOpen1 \-> Execute())  
![ExpandedBlockStart.gif][] \{  
![InBlock.gif][] edt1\->Text=dlgOpen1\->FileName;  
![InBlock.gif][] img1\->Picture\->LoadFromFile(edt1\->Text);  
![ExpandedBlockEnd.gif][] \}

2、逐行扫描图片，获取图片中每点的像素颜色值；  
color=img1->Canvas->Pixels\[i\]\[j\];

3、从获取的颜色值中提取R、G、B分量；  
rgbbuf\[0\]\[i\]\[j\]=GetRValue(color);  
rgbbuf\[1\]\[i\]\[j\]=GetGValue(color);  
rgbbuf\[2\]\[i\]\[j\]=GetBValue(color);

**BMP与JPG格式的相互转换**

函数代码如下,在程序头文件中加入：\#include <jpeg.hpp>

![None.gif][] void  bmptojpeg(TMemoryStream  \* pms)  
![ExpandedBlockStart.gif][] \{  
![InBlock.gif][] TJPEGImage \*j=new TJPEGImage;  
![InBlock.gif][] Graphics::TBitmap \*b=new Graphics::TBitmap;  
![InBlock.gif][] b\->LoadFromStream(pms);  
![InBlock.gif][] j\->Assign(b);  
![InBlock.gif][] j\->CompressionQuality=60; //等级太高有可能压缩出错！   
![InBlock.gif][] j\->Compress();  
![InBlock.gif][] pms\->Clear();  
![InBlock.gif][] j\->SaveToStream(pms);  
![InBlock.gif][] pms\->Position=0;  
![InBlock.gif][] delete b;  
![InBlock.gif][] delete j;  
![InBlock.gif][]  
![ExpandedBlockEnd.gif][] \}   
![None.gif][] void  jpegtobmp(TMemoryStream  \* pms)  
![ExpandedBlockStart.gif][] \{  
![InBlock.gif][] TJPEGImage \*j=new TJPEGImage;  
![InBlock.gif][] Graphics::TBitmap \*b=new Graphics::TBitmap;  
![InBlock.gif][]  
![InBlock.gif][] j\->LoadFromStream(pms);  
![InBlock.gif][] j\->DIBNeeded();  
![InBlock.gif][] b\->Assign(j);  
![InBlock.gif][] pms\->Clear();  
![InBlock.gif][] b\->SaveToStream(pms);  
![InBlock.gif][] pms\->Position=0;  
![InBlock.gif][]  
![InBlock.gif][] delete b;  
![InBlock.gif][] delete j;  
![InBlock.gif][]  
![ExpandedBlockEnd.gif][] \}

要将转换后的流保存成文件可以使用：SaveToFile方法保存；

[None.gif]: /images/20220514/c307cd0d2418410998e29be73d065fdb.png
[ExpandedBlockStart.gif]: /images/20220514/87cd906c442b4048b2fa885307a0d3bb.png
[InBlock.gif]: /images/20220514/c58fc90fb677499387186b48214498a7.png
[ExpandedBlockEnd.gif]: /images/20220514/85f9346b45a748f7afa9beae5ad927df.png