高分寻求－能把bmp图像如何压缩为JPG或jpeg的类

[wanglei15]

高分寻求－能把bmp图像如何压缩为JPG或jpeg的类

[nustchen]

http://www.vckbase.com/

[pcman1990]

去这里看看：http://www.vchelp.net/source/source_gra.htm

[xuying]

JPEG文件编码.把bitmap 格式压缩成JPEG格式
http://www.copathway.com/vchelp/view_article.asp?ft=2&article_id=269

[masterz]

#include <Stdio.h>
#include <Objbase.h>
#include <Windows.h>
#include <Gdiplus.h>
#include <GdiPlusEnums.h>
using namespace Gdiplus;
#pragma comment(lib,"gdiplus")
// Helper functions
int GetCodecClsid(const WCHAR*, CLSID*);

int main()
{
CLSID codecClsid;
EncoderParameters encoderParameters;
long quality;
Status stat;
GdiplusStartupInput gdiplusStartupInput;
ULONG gdiplusToken;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
{
// Get an image from the disk.
Image image(L"F:\\ddd.bmp");

// Get the CLSID of the JPEG codec.
GetCodecClsid(L"image/jpeg", &codecClsid);

// Before we call Image::Save, we must initialize an
// EncoderParameters object. The EncoderParameters object
// has an array of EncoderParameter objects. In this
// case, there is only one EncoderParameter object in the array.
// The one EncoderParameter object has an array of values.
// In this case, there is only one value (of type LONG)
// in the array. We will set this value to 0, 50, and 100.

encoderParameters.Count = 1;
encoderParameters.Parameter[0].Guid = EncoderQuality;
encoderParameters.Parameter[0].Type = EncoderParameterValueTypeLong;
encoderParameters.Parameter[0].NumberOfValues = 1;

// Save the image as a JPEG with quality level 0.
quality = 0;
encoderParameters.Parameter[0].Value = &quality;
stat = image.Save(L"Shapes001.jpg", &codecClsid, &encoderParameters);

if(stat == Ok)
wprintf(L"%s saved successfully.\n", L"Shapes001.jpg");
else
wprintf(L"%d Attempt to save %s failed.\n", stat, L"Shapes001.jpg");

// Save the image as a JPEG with quality level 50.
quality = 50;
encoderParameters.Parameter[0].Value = &quality;
stat = image.Save(L"Shapes050.jpg", &codecClsid, &encoderParameters);

if(stat == Ok)
wprintf(L"%s saved successfully.\n", L"Shapes050.jpg");
else
wprintf(L"%d Attempt to save %s failed.\n", stat, L"Shapes050.jpg");

// Save the image as a JPEG with quality level 100.
quality = 100;
encoderParameters.Parameter[0].Value = &quality;
stat = image.Save(L"Shapes100.jpg", &codecClsid, &encoderParameters);

if(stat == Ok)
wprintf(L"%s saved successfully.\n", L"Shapes100.jpg");
else
wprintf(L"%d Attempt to save %s failed.\n", stat, L"Shapes100.jpg");
}
GdiplusShutdown(gdiplusToken);
return 0;
} // main
int GetCodecClsid(const WCHAR* format, CLSID* pClsid)
{
UINT num = 0; // number of image encoders
UINT size = 0; // size of the image encoder array in bytes

ImageCodecInfo* pImageCodecInfo = NULL;

GetImageEncodersSize(&num, &size);
if(size == 0)
return -1; // Failure

pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
if(pImageCodecInfo == NULL)
return -1; // Failure

GetImageEncoders(num, size, pImageCodecInfo);

for(int j = 0; j < num; ++j)
{
if( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 )
{
*pClsid = pImageCodecInfo[j].Clsid;
return j; // Success
}
} // for

return -1; // Failure

} // GetCodecClsid
//download gdiplus.dll
//http://www.microsoft.com/downloads/release.asp?releaseid=32738
//Platform SDK Redistributable: GDI+ RTM

[pcman1990]

http://www.vckbase.com/code
jpeglib.zip可以显示JPEG文件，进行JPEG和BMP之间的相互转换，并可以保存为灰度JPG图像