Vision Worksheet 1
Image Processing 1: Binary Images and Detecting Connected Components

                                             Name ______________

Preliminary work:
        Read about image file formats PGM and PPM 
        Read about 4 and 8 connectivity  of   
        components in images.

1. A. Copy the image file: /home/ai/image1.pgm.  
   B. Load the image using xv and magnify sufficiently so you can
       see the 8 by 8 image.   (xv &   then right click for the menu)

2. A. Threshold the image so that all values below 100 are set to 0 and
      all values equal to or above 100 are set to 255.  Write the image
      to a file named "binary1.pgm".  Should look like this.
      This file should have the following header lines:
          P2
          # Comment line identifying this as a PGM binary imag, binary.pgm
          8 8
          255
          - the image pixel values should be here, 8 rows and 8 cols.
   
  B. View binary1.pgm with xv to check if the objects are
     in black against a white background.

3. A. Write a program connect4.lsp that labels and counts all "4-connected
      objects" in the picture.  Print both the binary image and the labeled 
      component image on the screen.
          View a sample output.

   B. Write connect8.lsp to label and count the "8-connected" objects
      in the image.