Convert Grayscale Image to Color Image Using Matlab

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From grayscale Image, how can I convert it to its original color. But not all the color. How can I convert it to its green, red, orange color. Is it possible. Any example?
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Chad Greene
Chad Greene on 25 Sep 2014
Each pixel in a grayscale image has a single value corresponding only to its brightness. That's all the information you have. RGB images have three values, corresponding to the brightness of red, green, and blue, and these three are combined to create the colors we all know and love. It's easy to convert RGB pixels to a single brightness value and call it grayscale, but after that pixel has been converted from three color values to a single value, it's an underdefined problem to try and convert it back. Unless you want to start making artistic decisions.

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Answers (2)

Image Analyst
Image Analyst on 25 Sep 2014
It doesn't restore the original colors, but the attached demo colorizes a freehand-drawn region. If you want something different, attach your grayscale image, describe the thing you want to colorize, and tell us how we are supposed to figure out the colors for each pixel.

Meshooo
Meshooo on 26 Sep 2014
Edited: Meshooo on 26 Sep 2014
There is no method that can do it for you fully automatically, but maybe possible if you can assume the other missing parameters.
So for example, if you have an old photo of a face taken many years ago when not color photos were available, then you can convert it to a colored image if you guess the missing color component. So lets say you will do it using the HSV color space. So you need:
H = hue, that you should guess for the color of the hair, lips, skin, etc.
S = Saturation, you can guess how much white or black you should add.
I = Intensity, you already have it from you gray image.
So in this way you can change your image from gray to colored image based in your color guess.
Hope that helps.

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