i need negative image

Hello .. I need help with transformation in grey level to transform cameraman.tiff image to negative version .. using Matlab code .. thanks

[Adam]

What have you done so far? Negating the image will depend on its data range, but when you have that it is a simple calculation.

[Miss SHOOSH]

I haven't done anything so far :( if you can help plz give me instructions or the code if you can .. Thanks for answering

[Adam]

Off the top of my head

doc imread
doc max

are all you really need beyond simple operations, although I'm not familiar with whether any specific scaling or shifting of the image data is done when negating it.

[Miss SHOOSH]

Ok Thanks .. anyone else can help? I have to apply negative transformation to the image cameraman.tif

Answer 1

[Image Analyst]

Try this with a uint8 image:

positiveImage = imread('CameraMan.tif');
negativeImage = 255 - positiveImage;

Answer 2

[VIBHOR AGARWAL]

You can also use MATLAB's in built function- `imcomplement(Image)` for this purpose.

Answer 3

[DGM]

It's best to avoid writing your code around unchecked assumptions of array class.

If you have Image Processing Toolbox, imcomplement() should work fine.

A = imread('peppers.png');
B = imcomplement(A);
imshow(B)

If you don't have IPT, MIMT iminv() (attached) does the same thing. It will work fine for images of any standard numeric/logical class. If you want to know how it works, just open it up and see.

A = imread('peppers.png');
B = iminv(A);
imshow(B)