Confused about the RGB colour coding
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Hello, I wonder if the Matlab RGB color index is just the usual RGB index divided by 255??? The default RGB color list is as follows in Matlab:
For example green is [0 1 0] the default RGB coding in the Colour software like Photoshop is [0 255 0] so do I just divide the color coding in Photoshop RGB format by 255 to arrive at the Matlab RGB color code?
I wonder if there is an inbuilt function like that... Thanks! D
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Accepted Answer
Jan
on 29 Sep 2011
If you store the RGB values as a [X, Y, 3] DOUBLE array, the values are going form 0 to 1. If you use an UINT8 array, the values are in the interval [0, 255], as in many other applications (Photoshop, color-pickers, HTML, etc).
A simple conversion:
RGB_double = rand(200, 100, 3);
RGB_uint8 = uint8(RGB * 255 + 0.5);
The 0.5 cares for the same weights of the UINT8(0) and UINT8(255) bins.
3 Comments
Image Analyst
on 29 Sep 2011
Yes. Dividing by 255 is fine. Or by intmax('uint16') if you're using 16 bit numbers.
Walter Roberson
on 29 Sep 2011
im2double() does the type-checking and divides by the appropriate scaling factor.
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