Starting with a grayscale image, how can I colour a certain pixel based on its x,y coordinates?

10 views (last 30 days)
I have a 256 by 256 grayscale image. I want to colour a certain coordinating (say 125,125) red. Do I need to convert the entire image into truecolour? I want to keep the greyscale image how it was other than the coloured pixel. Would gray2ind seems like the appropiate first step, but I'm not sure how to go from there.
Thanks in advanced!
  2 Comments
John BG
John BG on 29 Jun 2017
you don't have to convert the image to true color, but you can if the only code available you use can only work in one specific image format. Changing image format is easy in MATLAB.
Would you please supply a sample image so readers can show you different ways to alter single pixels.
Naim
Naim on 29 Jun 2017
Hey John thanks for your reply. I just want to add a colour pixel for testing purposes really. I didn't include a picture because the grayscale image I am using is irrelevant (I want to change specific pixels based on coordinates) but I went ahead and attached a photo anyway. Could you elaborate on how I could add the colour pixel to my grayscale photo? I'd appreciate the help!

Sign in to comment.

Answers (1)

Swarooph
Swarooph on 29 Jun 2017
Edited: Swarooph on 29 Jun 2017
Take a look at the question and answer here.
Note that grayscale images cannot have color pixels by definition. If you are just interested in marking a pixel with a marker you can use the plot function as discussed in the above answer's comments or use the insertMarker function.

Categories

Find more on Convert Image Type in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!