How to show a gray scale image with its contour in one figure?

Hello, guys:

I extracted two contours of a gray scale image, shown as following. But I can't make the contours shown upon the original gray scale imageg to get only one figure, I need a help, thanks a lot! The wanted result is like the third picture.

Answer 1

[Nils Speetzen]

Hi,

you should be able to achieve your goal using imfuse like this:

finalimage = imfuse(grayscaleimage, contour, 'blend');
imshow(finalimage)

The blend option uses alpha blending to combine both images.

I hope this works for you.

[Yaoting Yue]

I tried this, it's not work, the colorful contours would become white. I look for other solutions, and finally I make it, this function imoverlay() works it out.

Anyway, thank you very much!

Answer 2

[Image Analyst]

Try imshow() to display the image, then don't call subplot() or figure(). Just call "hold on" and then call plot() to plot the lines in the overlay above the figure.

imshow(grayImage);
hold on;
plot(x1, y1, 'm-'); % Draw magenta curve over image.
plot(x2, y2, 'g-'); % Draw green curve over image.

[Yaoting Yue]

There'is no function mapping for the contour, so it's difficult to use the plot(). I finally make it, this function imoverlay() is ok.

Anyway, thank you very much!

[Image Analyst]

Well how did you make those colored lines in the first place? You must have made them somehow before using imoverlay() if you were going to use their image as an input to imoverlay().

[Yaoting Yue]

Use contour = bwperim(X) to extract the contour of grayImage X.

[Image Analyst]

The gets the perimeter as an image, like bwboundaries() which gets the perimeters as a list of (x,y) coordinates. If you want to know how to use bwboundaries() and plot() to put up the lines in the overlay above the image, just ask.

Don't use contour as the name of your variable since it's the name of a built-in function.

[Yaoting Yue]

Thanks a lot! Yeah, After I got the list of (x,y) coordinates by using bwboundaries(), how to use plot() to put up the lines in the overlay above the image?