cximage.htm

一个很好用的图像编辑程序

    <TD><B>CxImgLib.dsw</B><BR>
      <IMG height=193 src="tree.png" 
      width=151></TD>
  </TR></TBODY></TABLE>
<P>To use CxImage in your project, you must edit these settings: </P>
<PRE>Project Settings
 |- C/C++
 |   |- Code Generation
 |   |   |- Use run-time library : Multithreaded DLL (must be the same for 
 |   |   |  all the linked libraries)
 |   |   |- Struct member alignment : must be the same for all the linked 
 |   |   |  libraries
 |   |- Precompiled headers : not using precompiled headers
 |   |- Preprocessor
 |       |- Additional Include Directories:  ..\cximage
 |- Link
    |- General
        |- Object/library modules: ../png/Debug/png.lib 
                                   ../jpeg/Debug/jpeg.lib 
                                   ../zlib/Debug/zlib.lib 
                                   ../tiff/Debug/tiff.lib 
                                   ../jasper/Debug/jasper.lib 
                                    ../cximage/Debug/cximage.lib  ...</PRE>
<P>
<H2>Adding your custom functions in CxImage<A name=custom></A></H2>
<P>Writing a new function for image processing is not so hard with CxImage. Here 
I'm going to describe <CODE>CxImage::Jitter</CODE>, it's very simple but it 
shows many aspects to take care when you work inside CxImage. The first thing, 
of course, is the declaration : <CODE>bool Jitter(long radius=2);</CODE> in the 
CXIMAGE_SUPPORT_DSP section of ximage.h, you can declare the function everywhere 
in the <CODE>public</CODE> scope of the class. And now the definition: </P><PRE>bool CxImage::Jitter(long radius)
{
    // check if the image is valid, this should be always the first line in 
    // the function 
    if (!pDib) return false;
    
    // local variables
    long nx,ny;
    
    // temporary image to store the partial results of the algorithm
    CxImage tmp(*this,pSelection!=0,true,true);
    
    // limit the effects of the functions only in the smallest rectangle that
    // holds the selected region (defined with the Selection...() functions ),
    // this will speed up the loops.
    long xmin,xmax,ymin,ymax;
    if (pSelection){
        xmin = info.rSelectionBox.left; xmax = info.rSelectionBox.right;
        ymin = info.rSelectionBox.bottom; ymax = info.rSelectionBox.top;
    } else {
        xmin = ymin = 0;
        xmax = head.biWidth; ymax=head.biHeight;
    }
    
    // main loop : scan the image in vertical direction
    for(long y=ymin; y &lt;ymax; y++){
    
        // monitor the progress of the loops
        info.nProgress = (long)(100*y/head.biHeight);
    
        // let the application a way to exit quickly
        if (info.nEscape) break;
    
        // main loop : scan the image in horizontal direction
        for(long x=xmin; x&lt;xmax; x++){
    
        // if the feature is enabled, process only the pixels inside the 
        // selected region
#if CXIMAGE_SUPPORT_SELECTION
            if (SelectionIsInside(x,y))
#endif //CXIMAGE_SUPPORT_SELECTION
            {
                // main algorithm
                nx=x+(long)((rand()/(float)RAND_MAX - 0.5)*(radius*2));
                ny=y+(long)((rand()/(float)RAND_MAX - 0.5)*(radius*2));
                if (!IsInside(nx,ny)) {
                    nx=x;
                    ny=y;
                }

                // save the result in the temporary image.
                // if you can, use PixelColor only for 24 bpp images,
                // and PixelIndex for 8, 4 and 1 bpp images : it's faster
                if (head.biClrUsed==0){
                    tmp.SetPixelColor(x,y,GetPixelColor(nx,ny));
                } else {
                    tmp.SetPixelIndex(x,y,GetPixelIndex(nx,ny));
                }

                // if the feature is enabled, process also the pixels 
                // in the alpha layer
#if CXIMAGE_SUPPORT_ALPHA
                tmp.AlphaSet(x,y,AlphaGet(nx,ny));
#endif //CXIMAGE_SUPPORT_ALPHA
            }
        }
    }

    // save the result and exit
    Transfer(tmp);
    return true;
}
</PRE>
<P><BR>
<H2>Examples: how to ...<A name=examples></A></H2>
<H2>... convert from a format to another</H2><PRE>CxImage  image;
// bmp -&gt; jpg
image.Load("image.bmp", CXIMAGE_FORMAT_BMP);
if (image.IsValid()){
    if(!image.IsGrayScale()) image.IncreaseBpp(24);
    image.SetJpegQuality(99);
    image.Save("image.jpg",CXIMAGE_FORMAT_JPG);
}
// png -&gt; tif
image.Load("image.png", CXIMAGE_FORMAT_PNG);
if (image.IsValid()){
    image.Save("image.tif",CXIMAGE_FORMAT_TIF);
}
</PRE>
<H2>... load an image resource</H2><PRE>//Load the resource IDR_PNG1 from the PNG resource type
CxImage* newImage = new CxImage();
newImage-&gt;LoadResource(FindResource(NULL,MAKEINTRESOURCE(IDR_PNG1),
                       "PNG"),CXIMAGE_FORMAT_PNG);</PRE>or<PRE>//Load the resource IDR_JPG1 from DLL
CxImage* newImage = new CxImage();
HINSTANCE hdll=LoadLibrary("imagelib.dll");
if (hdll){
    HRSRC hres=FindResource(hdll,MAKEINTRESOURCE(IDR_JPG1),"JPG");
    newImage-&gt;LoadResource(hres,CXIMAGE_FORMAT_JPG,hdll);
    FreeLibrary(hdll);
}</PRE>or<PRE>//Load a bitmap resource;
HBITMAP bitmap = ::LoadBitmap(AfxGetInstanceHandle(),
                              MAKEINTRESOURCE(IDB_BITMAP1)));
CxImage *newImage = new CxImage();
newImage-&gt;CreateFromHBITMAP(bitmap);</PRE>
<H2>... decode an image from memory</H2><PRE>CxImage image((BYTE*)buffer,size,image_type);</PRE>or<PRE>CxMemFile memfile((BYTE*)buffer,size);
CxImage image(&amp;memfile,image_type);</PRE>or<PRE>CxMemFile memfile((BYTE*)buffer,size);
CxImage* image = new CxImage();
image-&gt;Decode(&amp;memfile,type);</PRE>
<H2>... encode an image in memory</H2><PRE>long size=0;
BYTE* buffer=0;
image.Encode(buffer,size,image_type);
...
free(buffer);</PRE>or<PRE>CxMemFile memfile;
memfile.Open();
image.Encode(&amp;memfile,image_type);
BYTE* buffer = memfile.GetBuffer();
long size = memfile.Size();
...
free(buffer);</PRE>
<H2>... create a multipage TIFF</H2><PRE>CxImage *pimage[3];
pimage[0]=&amp;image1;
pimage[1]=&amp;image2;
pimage[2]=&amp;image3;

FILE* hFile;
hFile = fopen("multipage.tif","w+b");

CxImageTIF multiimage;
multiimage.Encode(hFile,pimage,3);

fclose(hFile);</PRE>or<PRE>FILE* hFile;
hFile = fopen("c:\\multi.tif","w+b");

CxImageTIF image;
image.Load("c:\\1.tif",CXIMAGE_FORMAT_TIF);
image.Encode(hFile,true);
image.Load("c:\\2.bmp",CXIMAGE_FORMAT_BMP);
image.Encode(hFile,true);
image.Load("c:\\3.png",CXIMAGE_FORMAT_PNG);
image.Encode(hFile);

fclose(hFile);
</PRE>
<H2>... copy/paste an image</H2><PRE>//copy
HANDLE hDIB = image-&gt;CopyToHandle();
if (::OpenClipboard(AfxGetApp()-&gt;m_pMainWnd-&gt;GetSafeHwnd())) {
    if(::EmptyClipboard()) {
        if (::SetClipboardData(CF_DIB,hDIB) == NULL ) {
            AfxMessageBox( "Unable to set Clipboard data" );
}    }    }
CloseClipboard();

//paste
HANDLE hBitmap=NULL;
CxImage *newima = new CxImage();
if (OpenClipboard()) hBitmap=GetClipboardData(CF_DIB);
if (hBitmap) newima-&gt;CreateFromHANDLE(hBitmap);
CloseClipboard();</PRE>
<H2>... display a file in a picture box</H2>
<PRE>HBITMAP m_bitmap = NULL;<br>CxImage image("myfile.png", CXIMAGE_FORMAT_PNG);
...
if (m_bitmap) DeleteObject(m_bitmap);<br>m_bitmap = image.MakeBitmap(m_picture.GetDC()-&gt;m_hDC);<br>m_picture.SetBitmap(m_bitmap);</PRE>
<H2>History and credits.<A name=history></A></H2>
<P>Starting form my <CODE>CxDib</CODE> class, that implements memory DIBs only, 
  I tried to add some members to read images from files. Looking for a solution, 
  I found a nice MFC class named <CODE>CImage</CODE> on the net, release 1.4 (1998). 
  <CODE>CImage</CODE> supports BMP, GIF, PNG and JPG, but suffers many little 
  bugs and uses a complex class structure, so I decided to strip it to the base 
  and merge <CODE>CxDib</CODE> with the <CODE>CImage</CODE> philosophy, to obtain 
  the new <CODE>CxImage</CODE> class. Also I updated the libraries for JPG, PNG 
  and ZLIB.<BR>
  With <CODE>CxImage</CODE> is very easy to add new image types, so I added the 
  TIFF library (rev. 6) and a minimal support for <CODE>ICON</CODE>s, MNG, TGA 
  and PCX. Finally I added some specific functions to obtain an image from global 
  <CODE>HANDLE</CODE>s (windows clipboard) and objects (windows resources).<BR>
  With the release 5, CxImage has now a good support for memory files, new methods 
  and file formats, and it is more portable.</P>
<ul>
  <li>CImage