Image Histogram Matching Using CDF

I wrote a code for image histogram matching using CDF (cumulative distribution function). However, the CDF of result image is differ from the reference image. Please, check the codes and inform me the problems. Note that image is not a 8 bit and has decimal places. Thanks.

reference % reference image
input % input image
re_k = unique(reference(:));
in_k = unique(input(:));
[x,y] = size(input);

[re_counts, re_bins] = hist(reference(:),re_k);
re_cdf = cumsum(re_counts) / sum(re_counts);
[in_counts, in_bins] = hist(input(:),in_k);
in_cdf = cumsum(in_counts) / sum(in_counts);

LU = interp1(re_cdf,re_bins,in_cdf);
test = interp1(re_bins, LU, in(:));

result = reshape(test,x,y);

[Tejas]

Hello YongHyun ,

There is a MATLAB function called ' imhistmatch ' which adjusts the histogram of an image to match N-bin histogram of a reference image. You can try to use this.

-Tejas