imgca (Image Processing Toolbox User's Guide)

Image Processing Toolbox User's Guide

Get handle to most recent current axis containing an image

Syntax

```
hax = imgca
hax = imgca(hfig)
```

Description

hax = imgca returns the handle of the of the most recent current axis that contains an image. The current axis may be in a regular figure window or in an Image Tool window.

If no figure contains an axis that contains an image, imgca creates a new axis.

hax = imgca(hfig) returns the handle to the current axis that contains an image in the specified figure (it need not be the current figure).

Note

imgca can be useful in getting the handle to the Image Tool axis. Because the Image Tool turns graphics object handle visibility off, you cannot retrieve a handle to the tool figure using gca.

Example

Label the coins in the image, compute their centroids, and superimpose the centroid locations on the image. View the results using imtool and imgca.

I = imread('coins.png');
figure, imshow(I)

bw = im2bw(I, graythresh(getimage));
figure, imshow(bw)

bw2 = imfill(bw,'holes');
L = bwlabel(bw2);
s = regionprops(L, 'centroid');
centroids = cat(1, s.Centroid);

Display original image I and superimpose centroids.

imtool(I)
hold(imgca,'on')
plot(imgca,centroids(:,1), centroids(:,2), 'r*')
hold(imgca,'off')

See also

gca, gcf, imgcf

imfinfo imgcf