Main Content

Rotate ROI in Image

This example shows how to apply rotation transformation to a region of interest (ROI) in the input image.

Example Model

Open the Simulink® model.

modelname = 'ex_rotatewarp.slx';

The model reads an input image by using the Image From File block. To apply rotation transformation to a particular region in the input image, you must

  • specify the rotation transformation matrix

  • specify the ROI

The model then rotates the selected ROI by using the Warp block with these parameter values:

  • Transformation matrix source - Input port. This enables the TForm input port. Specify the rotation transformation matrix value as $\left\lbrack \begin{array}{ccc}0\ldotp 9478 & 0\ldotp 3188 & 0\\-0\ldotp 3188 & 0\ldotp 9478 & 0\\0 & 0 & 1\end{array}\right\rbrack$ by using the Constant block.

  • Interpolation method - Bilinear

  • Background fill value - 0

  • Output image position source - Same as input image

  • Select the Enable ROI input port parameter. Specify the value for ROI input port as $\left\lbrack \begin{array}{c}94\;54\;100\;80\end{array}\right\rbrack$ by using the Constant block.

Simulate and Display Results

Run the model and display the results by using the Video Viewer block.