OpenCV. Copy image from unsigned char buffer, resize and save to file

How to copy image from unsigned char buffer, resize and save to file.
If you use single-channel image.

#include <opencv/cv.h>

#include <opencv/highgui.h>

                int coeff = 4;

                cv::Mat src( height, width, CV_8UC1, (void *) source_byte_beffer ) );

                cv::Mat small(height/ coeff, width/ coeff, CV_8UC1 );

                cv::Size s_half(width/ coeff, height/ coeff);

                cv::resize( src, small, s_half, 1, 1, cv::INTER_LINEAR ); // resize from src to small

                IplImage* writeImage;

                writeImage=cvCloneImage(&(IplImage)src);

                cvSaveImage("src1.bmp", writeImage);

                cvReleaseImage( &writeImage );

                writeImage=cvCloneImage(&(IplImage)small);

                cvSaveImage("little.bmp", writeImage);

                cvReleaseImage( &writeImage );

                //Another way of writtting:               

                /*cvWrite("src.bmp", src );

                cv::imwrite( "small.bmp", small );*/