View .bin file (YCbCr 4:2:2 format) - image

Question

I am given a .bin file. I know that the elements in this file correspond to Y Cb Cr values (4:2:2). Also, the data type is 8 bits. How can I view this?
I found a pretty good site: http://rawpixels.net/ which does what is expected but for YUV format. I want for YCbCr format.
Priliminary google search gives conversion to RGB, which is not desired.
I have attached an example .bin file on dropbox. The size of image is 720 X 576.

Answer 1

From Wikipedia
Y′CbCr is often confused with the YUV color space, and typically the
terms YCbCr and YUV are used interchangeably, leading to some
confusion; when referring to signals in video or digital form, the
term "YUV" mostly means "Y′CbCr".
If you are on a linux-based system and have access to ffmpeg, the following command correctly displays the data
ffplay -f rawvideo -video_size 720x576 -pix_fmt yuyv422 38.bin
Another good tool for displaying of RGB/YCbCr images is vooya which is free for linux but not for windows.
My own tool, yuv-viewer works as well.
Hope this helps.

Answer 2

You can up-sample the 4:2:2 down-sampled chroma like this:
////////////////////////////////////////////////////////////////////////////////
// unpack.c
// Mark Setchell
//
// Convert YCbCr 4:2:2 format file to full YCbCr without chroma subsampling
//
// Compile with:
// gcc -o unpack unpack.c
// Run with:
// ./unpack < input.bin > output.bin
////////////////////////////////////////////////////////////////////////////////
#include <stdio.h>
#include <sys/uio.h>
#include <unistd.h>
#include <sys/types.h>
int main(){
unsigned char ibuf[4]; // Input data buffer format: Y Cb Y Cr
unsigned char obuf[6]; // Output data buffer format: Y Cb Cr Y Cb Cr
// Read 4 bytes at a time, and upsample chroma
while(fread(ibuf,4,1,stdin)==1){
obuf[0]=ibuf[0];
obuf[1]=ibuf[1];
obuf[2]=ibuf[3];
obuf[3]=ibuf[2];
obuf[4]=ibuf[1];
obuf[5]=ibuf[3];
fwrite(obuf,6,1,stdout);
}
return 0;
}
Then you would run this to up-sample:
./unpack < input.bin > output.bin
and then use ImageMagick convert to get a PNG (or JPEG, or TIF) like this:
convert -size 720x576 -depth 8 yuv:result.bin image.png
In theory, ImageMagick should be able to do the up sampling itself (and not need a C program) with a command line like this, but I can't seem to make it work:
convert -interlace none -sampling-factor 4:2:2 -size 720x576 -depth 8 yuv:input.bin image.jpg
If anyone knows why - please comment!

Answer 3

This is a slightly different version of my other answer, insofar as it up-samples the chroma, and also converts the YUV to RGB and then creates a NetPBM PNM format file. That means that you only need to install the pnmtopng utility from NetPBM to get to a PNM image - and NetPBM is much lighter weight and simpler to install than ImageMagick.
////////////////////////////////////////////////////////////////////////////////
// yuv2pnm.c
// Mark Setchell
//
// Convert YUV 4:2:2 format file to RGB PNM format without chroma subsampling
//
// Compile with:
// gcc -o yuv2pnm yuv2pnm.c
//
// Run with:
// ./yuv2pnm < input.bin > output.pnm
//
// and then use ImageMagick to go to PNG format, or JPEG or TIF, with
//
// convert output.pnm image.png
//
// or, all in one line (still with ImageMagick) to JPEG:
//
// ./yuv2pnm < input.bin | convert pnm:- image.jpg
//
// or, use the (simpler-to-install) NetPBM's "pnmtopng" to convert to a PNG file
//
// ./yuv2pnm < input.bin | pnmtopng - > image.png
////////////////////////////////////////////////////////////////////////////////
#include <stdio.h>
#define MIN(a,b) (a<b) ? a : b
void YUV2RGB(unsigned char Y,unsigned char U, unsigned char V,unsigned char *RGB)
{
int R,G,B;
R = Y + (1.370705 * (V-128));
G = Y - (0.698001 * (V-128)) - (0.337633 * (U-128));
B = Y + (1.732446 * (U-128));
RGB[0] = MIN(255,R);
RGB[1] = MIN(255,G);
RGB[2] = MIN(255,B);
}
int main(int argc,char* argv[]){
unsigned char buf[4]; // Input data buffer format: Y Cb Y Cr
unsigned char RGB[6]; // Output data buffer format: R G B R G B
int width=720;
int height=576;
// Write PNM header
fprintf(stdout,"P6\n");
fprintf(stdout,"%d %d\n",width,height);
fprintf(stdout,"255\n");
// Read 4 bytes at a time, upsample chroma and convert to 2 RGB pixels
while(fread(buf,4,1,stdin)==1){
YUV2RGB(buf[0],buf[1],buf[3],&RGB[0]);
YUV2RGB(buf[2],buf[1],buf[3],&RGB[3]);
fwrite(RGB,6,1,stdout);
}
return 0;
}
NetPBM format is described here. Note PNM is an abbreviation that includes PPM.

Answer 4

Find below formula to convert YUV data into RGB.
R = Y + 1.4075 * (V - 128)
G = Y - 0.3455 * (U - 128) - (0.7169 * (V - 128))
B = Y + 1.7790 * (U - 128)