RGB2JPEG - Coverts from RGB format to the YCbCr format used by JPEG

Usage

YCbCr = rgb2jpeg(RGB);

Input parameters

Output parameters

Description

'rgb2jpeg(RGB)' performs a transformation of the 3d data-cube RGB with dimensions \(N \times M \times 3\), which contains information of the colours "red", "green" and "blue". The output variable YCbCr is a 3d data-cube of the same size containing information about "luminance", "chrominance blue" and "chrominance red". The output will be of the uint8 type.

See http://en.wikipedia.org/wiki/YCbCr and http://de.wikipedia.org/wiki/JPEG.

Examples:

In the following example, the Lichtenstein test image is split into its three components. The very first subplot is the original image:

f=lichtenstein;

f_jpeg=rgb2jpeg(f);

subplot(2,2,1);
image(f);axis('image');

Ymono=zeros(512,512,3,'uint8');
Ymono(:,:,1)=f_jpeg(:,:,1);
Ymono(:,:,2:3)=128;
fmono=jpeg2rgb(Ymono);
subplot(2,2,2);
image(fmono);axis('image');

Cbmono=zeros(512,512,3,'uint8');
Cbmono(:,:,2)=f_jpeg(:,:,2);
Cbmono(:,:,3)=128;
fmono=jpeg2rgb(Cbmono);
subplot(2,2,3);
image(fmono);axis('image');

Crmono=zeros(512,512,3,'uint8');
Crmono(:,:,3)=f_jpeg(:,:,3);
Crmono(:,:,2)=128;
fmono=jpeg2rgb(Crmono);
subplot(2,2,4);
image(fmono);axis('image');