Image Visualization

Building the Cantata Workspace

1. Read the image $DIP/data/gull.viff and display it using the operators User defined and Display Image
2. Extract a Region of Interest (ROI) around the seagull's eye using the Extract operator with the following parameters

   Region Size:   Width  10
                  Height 10
   Region Origin: Width 194
                  Height 23
   

3. Zoom the ROI image using the Expand operator. Select a proper magnification factor. Use the Display Image operator to visualize the "zoomed" data.
4. Print the pixel values of the ROI image (10 x 10) by first converting the image to ASCII format. Use operators Supported Formats and File Viewer.
5. Print the data using the Print Data operator in place of Supported Formats. The difference is that the "Print Data" operator prints each pixel in a line together with its coordinates.
6. Display a surface plot of the ROI image using the operator 3D Plot. Select the following parameters by clicking on the options button of the plot display window:

   Plot Type:        Constant Shade
   Rotation About X: 130
   Rotation About Z:   0
   Eye Distance:       1
   

7. Get a vertical intensity profile of the image using the Extract operator. In this case we are extracting the entire vertical line, thus it is not necessary to specify any parameters in the height direction. Select only the width parameters:

   Region Size:   Width  1
   Region Origin: Width 128
   

8. The vertical line extracted is a 1D signal. You can display it using the Display Image operator. This data can be better visualized using the 2D Plot operator.

Exercises

• Extract other ROIs of the image using the Interactive ROI Extraction operator instead of the Extract operator.

What you learned

• Extract and zoom an ROI of an image.
• Extract and plot a 1D intensity profile of an image.