Examining data

If you have displayed an image with `image', you can use `icur' to move a cursor over the image. Stop at a point of interest, and you can be told the coordinates and data value of that point.

   ICL> icur

   Use mouse to control cursor.
   Press "D" to display pixel data.
   Press space bar to record pixel.
   Press "Q" to exit.

      76.00000       143.0000       132.3220
      198.0000       184.0000       115.9024
      214.0000       34.00000       3.863415
   Pixel record #01 at   167    52   167.0000       52.00000
   Pixel record #02 at   155   195   155.0000       195.0000
   Pixel record #03 at    61   211   61.00000       211.0000

On the first three positions `d' was used, on the latter three the space bar. `Recording' a pixel does not tell you its brightness, but the position is stored for future use.

If you used `igrey' or `icont' to display, then you can use `igcur' in a similar way to find out about pixels.

Another useful inspection command is `istat'. It does not need any display, but works on the data directly.

   ICL> istat a_file accept

   Y-range 1 to 256
   X-range 1 to 256
   Total (over 65536.0 pixels) = 8.4904E+6
   Max   = 246.29   in pixel (89,47)
   Min   = 0        in pixel (215,35)
   Mean  = 129.55
   Sigma = 49.3974