Version 2.4 (R2007b) Video and Image Processing Blockset Release Notes

Version 2.4 (R2007b) Video and Image Processing Blockset

This table summarizes what's new in Version 2.4 (R2007b):

New features and changes introduced in this version are:

• Corner Detection Block Finds Corners in Images

• Demo Blocks Upgraded

• Demos Added and Updated

• Demo Recategorization

• Lucas-Kanade Method of Optical Flow Block Enhanced

• Performance Improvements

• Removed DirectX Component Registration Limitations of From Multimedia File, To Multimedia File, and To Video Display Blocks

• Rounding Modes Added

• Write AVI File Block Obsoleted

Corner Detection Block Finds Corners in Images

The Corner Detection block calculates the corner metric matrix and finds corners in images. For more information, see the Corner Detection block reference page.

Demo Blocks Upgraded

If you used the following demo blocks in your models, you need to update your models with the latest versions of these blocks. Because these blocks have been improved, you need to update their parameters to suit your applications.

Compatibility Considerations

Update your models with the latest versions of these blocks.

Demos Added and Updated

The Video and Image Processing Blockset contains three new or updated demos for R2007b.

Video Mosaicking Demo Added

The new Video Mosaicking demo shows how to stitch video frames together to form a mosaic image that provides a comprehensive view of a scene.

Pattern Matching Demo Allows User-Selected Tracking Target

The Target block in the Pattern Matching demo uses the Image Processing Toolbox imrect function to let you manually select the size and position of the region of interest you want to detect.

Traffic Warning Sign Recognition Demo Improvements

The Traffic Warning Sign Recognition demo now uses a more robust template matching technique to identify the signs. In addition, the demo now uses labels to show the detected signs.

Demo Recategorization

The Video and Image Processing Blockset demos have been recategorized into the following libraries.

Lucas-Kanade Method of Optical Flow Block Enhanced

The Optical Flow block now has two options for solving the optical flow constraint equation when you set the Method parameter to Lucas-Kanade:

• Difference filter [-1 1] — This was the only option available in previous releases, and is the default option.

• Derivative of Gaussian — This option is new in this release.

Use the new Temporal gradient filter parameter to select the filter option.

The Optical Flow block supports fixed-point data types when the Method parameter is set to Lucas-Kanade and the Temporal gradient filter parameter is set to Difference filter [-1 1].

For more information about these enhancements, see the Optical Flow block reference page.

Performance Improvements

The Video and Image Processing Blockset contains three performance enhancements for R2007b.

Label Block Has More Efficient Labeling Algorithm

The old block implementation was based on a flood-fill algorithm, while the new algorithm is union-find based. As a result, the new labeling algorithm uses less memory and is a more cache efficient.

Compatibility Considerations.   The new labeling algorithm might label the objects in the image with different label numbers.

Morphological Blocks Experience Speed Increase

The speed of simulation and the speed at which your generated code runs will increase, if you meet all of the following conditions:

• You are using any of the blocks in the Morphological Operations library except the Label block.

• You are working with intensity images.

• The structuring element you are using has four or more contiguous elements that form a horizontal line, a vertical line, or a shape that the block can decompose into a set of horizontal lines, vertical lines, or both.

For more information about structuring elements, see the strel function reference page in the Image Processing Toolbox documentation.

Row-Major Data Format Supported by Chroma Resampling, Deinterlacing, and Insert Text blocks

The Chroma Resampling, Deinterlacing, and Insert Text blocks give you the option to process data that is stored in row-major format when you select the Input image is transposed (data order is row major) check box. For more information, see the Chroma Resampling, Deinterlacing, and Insert Text block reference pages.

Removed DirectX Component Registration Limitations of From Multimedia File, To Multimedia File, and To Video Display Blocks

Previously, you were unable to use the From Multimedia File, To Multimedia File, or To Video Display blocks without first having someone with system administrator privileges register the DirectX components associated with these blocks on your Windows machine. This limitation has been removed.

Rounding Modes Added

The Rounding mode parameter on the Fixed-point pane of Video and Image Processing Blockset blocks now has two additional options, Zero and Ceiling. For more information about this parameter, see Rounding Methods in the Signal Processing Blockset User's Guide.

Write AVI File Block Obsoleted

The To Multimedia File block now supports AVI files on UNIX platforms. Consequently, the Write AVI File Block has been obsoleted to remove duplicate functionality.

Compatibility Considerations

Replace any instances of the Write AVI File block with the To Multimedia File block.

Version 2.5 (R2008a) Video and Image Processing Blockset

Version 2.3 (R2007a) Video and Image Processing Blockset