Unsing ginput to reading pixel in graylevel image

Hi,

I wondered if anyone knows a function or method used to read the pixel values in an image. Here is what I mean. I have a gray-level image, and I can use the ginput function to select the coordinates. How can I use the ginput to read the intensity value in the gray image as "live" or before select the position? The reason for doing this, I want to know what is the highest intensity value that my ginput pointing to. As you know, some images gradient in the intensity value.

I was reading to the ginput code itself, but I only could change the arrow color instead of black to red. I could not understand or modify the code itself to read the intensity value when I point to the intensity area in the image.

[DGM]

If your goal is to find the point of highest intensity, why are you using ginput to do it manually? Are you trying to find the highest intensity in a particular user-selected local region? If so, you should realize that you're not likely to have a very good time finding it if your image is scaled for display.

Assuming that's the actual root purpose, you can just define an ROI and find the max within that. For example:

inpict = imread('coins.png');

s = size(inpict);
imshow(inpict); hold on;
P = drawpolygon(); % select one of the coins with a polygon selection

maskedpict = inpict.*uint8(createMask(P));
[mx idx] = max(maskedpict(:)) % max value and linear index
[row col] = ind2sub(s(1:2),idx) % or row and column subs

delete(P);
plot(col,row,'bo') % show max location

Otherwise, you might want to clarify.

[Sara]

Thank you for your answer.

I am sorry I was not clear about why I use ginput.

The image that I have is a bend close to the periphery. I want to plot the intensity profile for the column that is close to the periphery. I mange that, but I needed a more accurate way to select the coordinates.

Here is an attached for the image that I work on it. As you can see the image is bending.

I use the gunput to slelect 3 points (or more )in the clumns and plot the slection in the improfile funcation. Now I want to use ginput where is the highest intsity so that I can select it.

NOTE: The image is a colored map to show the intensity changing along with the columns.

Answer 1

[Image Analyst]

Call impixelinfo():

imshow(yourImage);
impixelinfo; % Show "live" status bar on figure with (x,y) and RGB or gray scale.

[Sara]

Thank you for your answer,

I will get to the function that you suggestion.

[Image Analyst]

You're welcome. Can you please "Accept this answer" if it worked for you.