Geometric transform on an object

 htrans2 = vision.GeometricTransformer;
 img2 = checker_board(20,10);
 tfMat=[1      0     -15*2     0      1      15*2; ...
        0.4082 0      15*2    -0.4082 1.0204 35*2; ...
        1     -0.4082 5.4082*2 0      0.4082 44.5918*2]';

 polyROI  = [50  0 50 49 99 49 99 0; ...
              0  0  0 49 49 49 49 0; ...
             50 50 50 99 99 99 99 50]' * 2;

 htrans2.BackgroundFillValue = [0.5 0.5 0.75];
 htrans2.ROIInputPort = true;
 htrans2.ROIShape = 'Polygon ROI';
 transimg2 = step(htrans2,img2,tfMat,polyROI);
 imshow(img2);
 figure;imshow(transimg2);