How to convert 8 bit IplImage to 24 bit IplImage in OpenCV?

Question

I have an 8 bit IplImage and I want to convert it to a 24 bit IplImage. How can I do this?

Answer 1

Assuming your gray image is in a variable called image -

IplImage *rgbimage = cvCreateImage(/*whatever size*/, 8, 3);
cvCvtColor(image, rgbimage, CV_GRAY2BGR); 

Answer 2

You need cvConvertScale this is an example from this question

    IplImage *im8 = cvLoadImage(argv[1]);
    IplImage *im32 = cvCreateImage(cvSize(im8->width, im8->height), 32, 3);

    cvConvertScale(im8, im32, 1/255.);

Answer 3

Here you go,

Mat input_8Bit;
vector <Mat> Vec_temp_8bit;

Vec_temp_8bit.push_back ( input_8Bit );
Vec_temp_8bit.push_back ( input_8Bit );
Vec_temp_8bit.push_back ( input_8Bit );

Mat Output_24Bit;

merge ( Vec_temp_8bit, Output_24Bit );

Please give a try, I havent checked it. But logically it should work!