imcomplement function (Negative of an image)

imcomplement computes the complement of the image IM. IM can be a binary, intensity, or RGB image. IM2 has the same class and size as IM.
 
first the highest intensity value is computer for a pixel which is 255 and then the pixel value is subtracted from that highest values.

General Example

>> A = uint8([5 6 9 11 13]);
>> B = imcomplement(A)

B =

  250  249  246  244  242

Operation on images as

>> oimgRGB = imread('Desert.jpg');
>> gImg = rgb2gray(oimgRGB);
>> imgCompl = imcomplement(gImg);
>> subplot(1,2,1),imshow(gImg)
>> subplot(1,2,2),imshow(imgCompl)

Output

Example with color images

>> oimgRGB = imread('sampleImage.jpg');
>> imgCompl = imcomplement(oimgRGB);
>> subplot(1,2,1),imshow(oimgRGB)
>> subplot(1,2,2),imshow(imgCompl)

Output