Re: Separating image band alters histogram

[Terry Duell]

On Sun, 30 Sep 2012 00:51:22 +1000, Carnë Draug <address@hidden>  
wrote:


> I don't understand the problem, it's the purpose of mat2gray to change
> the histogram since it sets the minimum and max to the minimum and max
> of the image. Unless the min and max of your image are 0 and 1, they
> will be changed.

OK, that's the bit I didn't understand, and explains the result.
> If you want to get each channel without modification, just pass the
> channel, without any function.
>
> imwrite (I1(:,:,1)), "sep-band/red.tif");
>
> Does that works?

Yes, it gives the expected result.

> Also, when you have an image of the uint8 class and wish to convert it
> to class double, you should divide by 255 and not 256. Or use
> im2double which already thinks about this things for you.

OK.

Thanks for your help.

Cheers,
--
Regards,
Terry Duell