Problem with rotating an image

Hi,

I have a code within app designer which is aim in rotating an object but I get sometimes this error:

c

 =
 
   1.0e+03 *
 
    1.0595    1.0271
 
Intermediate dot '.' indexing produced a comma-separated list with 2 values, but it must produce a single value
when followed by subsequent indexing operations.
 
Error in RotateV/ManualrotateButtonPushed (line 765)
            xCentre = stat.Centroid(1);
 
Error in matlab.apps.AppBase>@(source,event)executeCallback(ams,app,callback,requiresEventData,event) (line 62)
            newCallback = @(source, event)executeCallback(ams, ...
 
Related documentation
 
Error while evaluating Button PrivateButtonPushedFcn.

The relevant code is:

[B,L] = bwboundaries(app.Iworking,'noholes');
k=1;
stat = regionprops(L,"Centroid","MajorAxisLength","Orientation","MinFeretProperties","MaxFeretProperties");
b = B{k};
c = stat(k).Centroid;
app.yBoundary = b(:,2);
app.xBoundary = b(:,1);
cy = c(:,2);
cx = c(:,1);

app.IManualAngleRotImg = imrotate(app.Iworking, app.rotateEditField.Value);

[B,L] = bwboundaries(app.IManualAngleRotImg,'noholes');
k=1;
stat = regionprops(L,"Centroid","MajorAxisLength","Orientation","MinFeretProperties","MaxFeretProperties");
b = B{k};
c = stat(k).Centroid
app.yBoundary = b(:,2);
app.xBoundary = b(:,1);

cy = c(:,2);
cx = c(:,1);

imshow(app.IManualAngleRotImg,'Parent', app.objectRotateEditorAxes)
hold(app.objectEditorAxes,'on');

plot(app.objectRotateEditorAxes, app.yBoundary, app.xBoundary, 'red', 'linewidth', 2);
hlen = stat.MajorAxisLength;
xCentre = stat.Centroid(1);
yCentre = stat.Centroid(2);

Any idea how can I solve it? is it related to the "1.0e+03 *" outcome, Can someone help?

Thanks a lot

Answer 1

[Image Analyst]

stat is a structure array, not a single structure.

Try this

xy = vertcat(stat.Centroid); % Get all N blobs centroids into an N by 2 array with x=column1 and y=column2.
cx = xy(:, 1); % Or xCenter = xy(:, 1);
cy = xy(:, 2); % Or yCenter = xy(:, 2);

[Ely Raz]

Hi,

Thanks.

I was applying your comments and also fixed the Orientation issue. I think the structure array issue is repetitive in all the script as I get this error with this line

line(app.objectRotateEditorAxes, [stat.MaxFeretCoordinates(1),stat.MaxFeretCoordinates(2)],[stat.MaxFeretCoordinates(3),stat.MaxFeretCoordinates(4)],'Color','blue','LineWidth',2);

Error using GMRotateVer11/ManualrotateButtonPushed
Intermediate dot '.' indexing produced a comma-separated list with 5 values, but it must produce a single value
when followed by subsequent indexing operations.

Any idea how can I solve this error as I presume it will occur also with MinFeretCoordinates?

Thanks a lot again and I highly appriciate it.

Code:

 function ManualrotateButtonPushed(app, event)
 
            [B,L] = bwboundaries(app.Iworking,'noholes');
            k=1;
            stat = regionprops(L,"Centroid","MajorAxisLength","Orientation","MinFeretProperties","MaxFeretProperties");
            b = B{k};
            c = stat(k).Centroid;
            app.yBoundary = b(:,2);
            app.xBoundary = b(:,1);
            cy = c(:,2);
            cx = c(:,1);
 
            app.IManualAngleRotImg = imrotate(app.Iworking, app.rotateEditField.Value);
 
            [B,L] = bwboundaries(app.IManualAngleRotImg,'noholes');
            k=1;
            stat = regionprops(L,"Centroid","MajorAxisLength","Orientation","MinFeretProperties","MaxFeretProperties");
            b = B{k};
            c = stat(k).Centroid;
            app.yBoundary = b(:,2);
            app.xBoundary = b(:,1);
 
            cy = c(:,2);
            cx = c(:,1);
 
            imshow(app.IManualAngleRotImg,'Parent', app.objectRotateEditorAxes)
            hold(app.objectEditorAxes,'on');
 
            plot(app.objectRotateEditorAxes, app.yBoundary, app.xBoundary, 'red', 'linewidth', 2);
            hlen = stat.MajorAxisLength;
            xy = vertcat(stat.Centroid);  % Get all N blobs centroids into an N by 2 array with x=column1 and y=column2.
            xCentre = xy(:, 1);
            yCentre = xy(:, 2);
 
 
            oriTemp = vertcat(stat.Orientation);
            ori = oriTemp(1, 1);
            % cosOrient = cosd(stat.Orientation);
            % sinOrient = sind(stat.Orientation);
            cosOrient = cosd(ori);
            sinOrient = sind(ori);
            xcoords = xCentre + hlen * [cosOrient -cosOrient];
            ycoords = yCentre + hlen * [-sinOrient sinOrient];
 
            line(app.objectRotateEditorAxes, xcoords, ycoords, 'Color','magenta','LineWidth',2);
            line(app.objectRotateEditorAxes, [stat.MaxFeretCoordinates(1),stat.MaxFeretCoordinates(2)],[stat.MaxFeretCoordinates(3),stat.MaxFeretCoordinates(4)],'Color','blue','LineWidth',2);
            line(app.objectRotateEditorAxes, [stat.MinFeretCoordinates(1),stat.MinFeretCoordinates(2)],[stat.MinFeretCoordinates(3),stat.MinFeretCoordinates(4)],'Color','green','LineWidth',2);
            app.orientationAngleLabel.Text = strcat("Orientation angle: ", num2str(stat.Orientation));
            app.minFeretangleLabel.Text = strcat("Min. Feret angle: ", num2str(stat.MinFeretAngle));
            app.maxFeretangleLabel.Text = strcat("Max. Feret angle: ", num2str(stat.MaxFeretAngle));
 
            app.Iworking = app.IManualAngleRotImg;
            app.outline2save  = [app.yBoundary  app.xBoundary]
            %imshow(app.Iworking);
        end

[Image Analyst]

Again, stat is a structure ARRAY, not a single structure so you're going to have to give an index. If you want to do it like you're doing, stat would have to be a table. To do that add the 'table' option to regionprops.