Imshow(Image,Map) remap pixel intensities

Hello,

I have an image and a map which is a column vector with 256 rows. Each row says what the new pixel value should be for example below.

row - pixel intensity

1 - 0

2 - 0.5

3 - 1

So for the above, a pixel with intensity 0 should get mapped to 0 and pixel intensity of 1 should get mapped to 0.5 because matlab indexing starts from 1. I tried using matlab function imshow(image,map) but it does not work. Help please

Answer 1

[Walter Roberson]

MappedIntensity = MapArray(double(Intensity)+1);
image(MappedIntensity);
colormap(gray(256))

Answer 2

[Image Analyst]

There is a function specially made for this. It's called intlut. It remaps the gray levels according to a look up table (which you called map) just like you want. Here is the code:

remappedImage = intlut(originalGrayImage, map);

However it only works with integers, so for your example you'd have to multiply your map by 2 and then divide the image by 2

remappedImage = intlut(originalGrayImage, uint8(2*map)) / 2;