Compressing IplImage to JPEG using libjpeg in OpenCV

Question

So I have this problem. I have an IplImage that i want to compress to JPEG and do something with it. I use libjpeg. I found a lot of answers \"read through examples and docs

Answer 1

After fighting with libJpeg for 2 days (pointers, memory stepping, and pulling hair) I gave up and used the all favourite save-to-disk-load-to-memory approach, so if anybody is interested here is the method:

char* convert2jpeg(IplImage* frame, int* frame_size) {

FILE* infile = NULL;
struct stat fileinfo_buf;

if (cvSaveImage(name_buf, frame) < 0) {
    printf("\nCan't save image %s", name_buf);
    return NULL;
}

if (stat(name_buf, &fileinfo_buf) < 0) {
    printf("\nPLAYER [convert2jpeg] stat");
    return NULL;
}

*frame_size = fileinfo_buf.st_size;
char* buffer = (char *) malloc(fileinfo_buf.st_size + 1);

if ((infile = fopen(name_buf, "rb")) == NULL) {
    printf("\nPLAYER [convert2jpeg] fopen %s", name_buf);
    free(buffer);
    return NULL;
}

fread(buffer, fileinfo_buf.st_size, 1, infile);
fclose(infile);

return buffer;
}

I hope somebody finds this usefull. I wish somebody from OpenCV developers sees this thread and implements direct to buffer JPEG conversion in OpenCV and spares us the misery and 1 save/load to disk operation.