Image Statistics

Building the Cantata Workspace

1. Read the image gull.viff and display it using the operators User defined and Display Image.
2. Get the main statistics of the gull image using the Statistics operator. Show the contents of the statistics in an ASCII output file using the operator File Viewer.
3. Take the histogram of the original image using the Histogram operator. Plot the histogram using the 2D Plot operator.
4. Repeat the steps above using the floating point image spine.viff. Compute the histogram from 1000 to 2000 using 100 bins.

Exercises

• Display and take the histogram of the image lenina.viff. What are the minimum and maximum pixels values of the image? What you can say regarding the range of gray-level used in the digitalization of this image? Why is the minimum value not zero and why so many values equal to 255? Can you give name those effects?
• Display and take the histogram of the image musc1.viff. How many different cell population can you find in the image. Are they represented clearly in the histogram?

What you learned

• Histogram of an image.
• Obtain the statistic parameters of an image
• Interpret the histogram of an image.