libjpeg从内存生成iplimage

// depress_form_mem.cpp : 定义控制台应用程序的入口点。 // #include "stdafx.h" #include <iostream> #include <stdio.h> #include "cv.h" #include "opencv2/opencv.hpp" extern "C"{ #include "jpeglib.h" }; #pragma comment(lib,"libjpeg.lib") using namespace std; using namespace cv; #pragma pack(2) //两字节对齐，否则bmp_fileheader会占16Byte struct bmp_fileheader { unsigned short bfType; //若不对齐，这个会占4Byte unsigned long bfSize; unsigned short bfReverved1; unsigned short bfReverved2; unsigned long bfOffBits; }; struct bmp_infoheader { unsigned long biSize; unsigned long biWidth; unsigned long biHeight; unsigned short biPlanes; unsigned short biBitCount; unsigned long biCompression; unsigned long biSizeImage; unsigned long biXPelsPerMeter; unsigned long biYpelsPerMeter; unsigned long biClrUsed; unsigned long biClrImportant; }; FILE *input_file; FILE *output_file; void write_bmp_header(j_decompress_ptr cinfo) { struct bmp_fileheader bfh; struct bmp_infoheader bih; unsigned long width; unsigned long height; unsigned short depth; unsigned long headersize; unsigned long filesize; width=cinfo->output_width; height=cinfo->output_height; depth=cinfo->output_components; if (depth==1) { headersize=14+40+256*4; filesize=headersize+width*height; } if (depth==3) { headersize=14+40; filesize=headersize+width*height*depth; } memset(&bfh,0,sizeof(struct bmp_fileheader)); memset(&bih,0,sizeof(struct bmp_infoheader)); //写入比较关键的几个bmp头参数 bfh.bfType=0x4D42; bfh.bfSize=filesize; bfh.bfOffBits=headersize; bih.biSize=40; bih.biWidth=width; bih.biHeight=height; bih.biPlanes=1; bih.biBitCount=(unsigned short)depth*8; bih.biSizeImage=width*height*depth; fwrite(&bfh,sizeof(struct bmp_fileheader),1,output_file); fwrite(&bih,sizeof(struct bmp_infoheader),1,output_file); if (depth==1) //灰度图像要添加调色板 { unsigned char *platte; platte=new unsigned char[256*4]; unsigned char j=0; for (int i=0;i<1024;i+=4) { platte[i]=j; platte[i+1]=j; platte[i+2]=j; platte[i+3]=0; j++; } fwrite(platte,sizeof(unsigned char)*1024,1,output_file); delete[] platte; } } void write_bmp_data(j_decompress_ptr cinfo,unsigned char *src_buff) { unsigned char *dst_width_buff; unsigned char *point; unsigned long width; unsigned long height; unsigned short depth; width=cinfo->output_width; height=cinfo->output_height; depth=cinfo->output_components; dst_width_buff=new unsigned char[width*depth]; memset(dst_width_buff,0,sizeof(unsigned char)*width*depth); point=src_buff+width*depth*(height-1); //倒着写数据，bmp格式是倒的，jpg是正的 for (unsigned long i=0;i<height;i++) { for (unsigned long j=0;j<width*depth;j+=depth) { if (depth==1) //处理灰度图 { dst_width_buff[j]=point[j]; } if (depth==3) //处理彩色图 { dst_width_buff[j+2]=point[j+0]; dst_width_buff[j+1]=point[j+1]; dst_width_buff[j+0]=point[j+2]; } } point-=width*depth; fwrite(dst_width_buff,sizeof(unsigned char)*width*depth,1,output_file); //一次写一行 } } void mem_init_source(j_decompress_ptr cinfo) { // cinfo->src->bytes_in_buffer = g_buf_len; // cinfo->src->next_input_byte = (unsigned char*)g_buf; } boolean mem_fill_input_buffer(j_decompress_ptr cinfo) { return true; } void mem_skip_input_data(j_decompress_ptr cinfo, long num_bytes) { cinfo->src->bytes_in_buffer -= num_bytes; cinfo->src->next_input_byte += num_bytes; } boolean mem_resync_to_restart(j_decompress_ptr cinfo, int desired) { return jpeg_resync_to_restart(cinfo, desired); } void mem_term_source(j_decompress_ptr cinfo) { } void analyse_jpeg(char *data, int size, IplImage ** img) { struct jpeg_decompress_struct cinfo; struct jpeg_error_mgr jerr; JSAMPARRAY buffer; unsigned char *src_buff; unsigned char *point; /* cinfo.err=jpeg_std_error(&jerr); jpeg_create_decompress(&cinfo); //jpeg_stdio_src(&cinfo,input_file); jpeg_mem_src(&cinfo, (unsigned char *)data, size); jpeg_read_header(&cinfo,TRUE); jpeg_start_decompress(&cinfo); */ jpeg_source_mgr jmgr; cinfo.err = jpeg_std_error(&jerr); jpeg_create_decompress(&cinfo); jmgr.init_source = mem_init_source; jmgr.fill_input_buffer = mem_fill_input_buffer; jmgr.skip_input_data = mem_skip_input_data; jmgr.resync_to_restart = mem_resync_to_restart; jmgr.term_source = mem_term_source; jmgr.next_input_byte = (unsigned char*)data; jmgr.bytes_in_buffer = size; cinfo.src = &jmgr; int ret = jpeg_read_header(&cinfo, TRUE); jpeg_start_decompress(&cinfo); int nRowSize = cinfo.output_width * cinfo.output_components; int w =cinfo.output_width; int h =cinfo.output_height; char *bmpBuffer=new char[h*w*3]; JSAMPARRAY pBuffer = (*cinfo.mem->alloc_sarray) ((j_common_ptr) &cinfo, 1, nRowSize, 1); while(cinfo.output_scanline < cinfo.output_height) { jpeg_read_scanlines(&cinfo, pBuffer, 1); int start=nRowSize*(cinfo.output_scanline-1); for(int i=0;i<nRowSize;i++) { bmpBuffer[start+i]=pBuffer[0][i]; } } printf("image width and height:%d,%d\n", cinfo.output_width, cinfo.output_height); unsigned long width=cinfo.output_width; unsigned long height=cinfo.output_height; unsigned short depth=cinfo.output_components; src_buff=new unsigned char[width*height*depth]; memset(src_buff,0,sizeof(unsigned char)*width*height*depth); /* buffer=(*cinfo.mem->alloc_sarray) ((j_common_ptr)&cinfo,JPOOL_IMAGE,width*depth,1); point=src_buff; while (cinfo.output_scanline < cinfo.output_height) { jpeg_read_scanlines(&cinfo,buffer,1); //读取一行jpg图像数据到buffer memcpy(point,*buffer,width*depth); //将buffer中的数据逐行给src_buff point+=width*depth; //一次改变一行 } */ //write_bmp_header(&cinfo); //写bmp文件头 //write_bmp_data(&cinfo, (unsigned char *)bmpBuffer); //写bmp像素数据 IplImage *_pImg = cvCreateImage(cvSize(w,h), 8, 3); printf("wid:%d, widstep:%d\n",_pImg->width, _pImg->widthStep); for (h=0; h<_pImg->height; h++) { for (w = 0; w < (_pImg->width * 3); w++) { *(_pImg->imageData+h*_pImg->widthStep+w+0)=*(bmpBuffer+3 * h * _pImg->width+w); //*(_pImg->imageData+h*_pImg->widthStep+w+1)=*(bmpBuffer+3 * h * _pImg->width+w); //*(_pImg->imageData+h*_pImg->widthStep+w+2)=*(bmpBuffer+3 * h * _pImg->width+w); } } cvCvtColor(_pImg, _pImg, CV_RGB2BGR); *img = cvCloneImage(_pImg); cvReleaseImage(&_pImg); jpeg_finish_decompress(&cinfo); jpeg_destroy_decompress(&cinfo); delete[] src_buff; } int main() { const char *input_file="d.jpg"; //output_file=fopen("lena.bmp","wb"); char buffer[256*1024] = {0}; //char buffer[256]; IplImage *timg = cvLoadImage("a.jpg", 1); cvShowImage("c", timg); cvWaitKey(); Mat mat = Mat::zeros(timg->height, timg->width, CV_8UC3); CvMat cmat; //cvConvert(timg, &cmat); //cvConvertImage(timg, &mat, CV_CVTIMG_FLIP); Mat test = cvarrToMat(timg, 0, 1, 0); imshow("mat", test); waitKey(); return 0; FILE * file = fopen(input_file, "rb"); int len = fread(buffer, sizeof(char), 256 * 1024, file); fclose(file); IplImage *img = NULL; char data[128*1024] = {0}; data[0] = buffer[0]; data[1] = buffer[1]; char *tmp = buffer + 2; int length = 0; while ((unsigned char)*tmp == 0xFF && (unsigned char)*(tmp + 1) >= 0xE0 && (unsigned char)*(tmp + 1) <= 0xEF) { tmp += 2; length = ((unsigned char)*tmp << 8) + (unsigned char)*(tmp + 1); tmp += (length + 2); len -= (length + 4); } tmp -= 2; int i = 0; for (i = 0; i < len; i++) { data[i + 2] = *tmp++; } analyse_jpeg(data, i + 2, &img); cvShowImage("pimg", img); cvWaitKey(); //fclose(output_file);