MFC JPG图片转单色位图代码
时间: 2023-06-02 14:02:46 浏览: 58
以下是MFC JPG图片转单色位图的代码:
1. 首先,需要引用头文件:
#include "stdafx.h"
#include "Jpeg.h"
#include "jpeglib.h"
2. 然后,定义一个函数来读取JPG文件并将其转换为单色位图:
BOOL CJpeg::JpgToMonoBmp(LPCTSTR lpszJpgFile, LPCTSTR lpszBmpFile)
{
BOOL bRet = FALSE;
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
FILE * infile;
JSAMPARRAY buffer;
int row_stride;
if ((infile = fopen(lpszJpgFile, "rb")) == NULL) {
return FALSE;
}
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, infile);
(void)jpeg_read_header(&cinfo, TRUE);
cinfo.out_color_space = JCS_GRAYSCALE;
(void)jpeg_start_decompress(&cinfo);
row_stride = cinfo.output_width * cinfo.output_components;
buffer = (*cinfo.mem->alloc_sarray)
((j_common_ptr)&cinfo, JPOOL_IMAGE, row_stride, 1);
BITMAPFILEHEADER bmpFileHeader = {0};
bmpFileHeader.bfType = 0x4D42; // "BM"
bmpFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
bmpFileHeader.bfSize = bmpFileHeader.bfOffBits + cinfo.output_width * cinfo.output_height;
BITMAPINFOHEADER bmpInfoHeader = {0};
bmpInfoHeader.biSize = sizeof(BITMAPINFOHEADER);
bmpInfoHeader.biWidth = cinfo.output_width;
bmpInfoHeader.biHeight = cinfo.output_height;
bmpInfoHeader.biPlanes = 1;
bmpInfoHeader.biBitCount = 1;
bmpInfoHeader.biCompression = BI_RGB;
bmpInfoHeader.biSizeImage = bmpFileHeader.bfSize - bmpFileHeader.bfOffBits;
FILE* fp = NULL;
if ((fp = fopen(lpszBmpFile, "wb")) == NULL) {
goto Exit;
}
fwrite(&bmpFileHeader, sizeof(BITMAPFILEHEADER), 1, fp);
fwrite(&bmpInfoHeader, sizeof(BITMAPINFOHEADER), 1, fp);
while (cinfo.output_scanline < cinfo.output_height) {
(void)jpeg_read_scanlines(&cinfo, buffer, 1);
for (int i = 0; i < row_stride; i++) {
BYTE bValue = buffer[0][i];
for (int j = 0; j < 8; j++) {
BYTE bPixel = ((bValue & (1 << j)) != 0) ? 255 : 0;
fwrite(&bPixel, sizeof(BYTE), 1, fp);
}
}
}
bRet = TRUE;
Exit:
(void)jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);
if (fp != NULL) {
fclose(fp);
}
return bRet;
}
3. 最后,调用该函数即可:
CJpeg jpg;
jpg.JpgToMonoBmp(_T("test.jpg"), _T("test.bmp"));
这将读取名为“test.jpg”的JPG文件并将其转换为单色位图,然后将结果保存在名为“test.bmp”的文件中。