NAME

pixlocate -- Print positions of all points inside (or outside) a specified range.

USAGE

pixlocate input lowerlimit upperlimit

DESCRIPTION

This task prints the coordinates and value of any pixel in an image where the value is within a specified range. As an alternative, the user may specify that the coordinates be printed when the value is outside the range. The user may also disable either end of the range to allow the task to look for pixels either above or below a specified value, with no limit on the range itself. A limit may be set on the number of pixels for which to print coordinates. Images with more than two dimensions may be processed.

PARAMETERS

input [file name]

Name of the input image.

lowerlimit = INDEF [real]

Coordinates will be printed if the value is greater than or equal to lowerlimit. (If outside = yes, however, coordinates will be printed if the value is less than or equal to lowerlimit.) If this is INDEF then the lower limit is not checked.

upperlimit = INDEF [real]

Coordinates will be printed if the value is less than or equal to upperlimit. (If outside = yes, however, coordinates will be printed if the value is greater than or equal to upperlimit.) If this is INDEF then the upper limit is not checked.

(maxvals = 1000) [integer, min=1]

Maximum number of points whose coordinates should be printed. If more points than this are found, the task writes the message "# maximum exceeded" to STDERR and quits.

(border = 0) [integer, min=0]

Width of the border around all axes. Pixels closer than this to the ends of the axes are ignored.

(outside = no) [boolean]

Print pixels with values outside the range [lowerlimit to upperlimit]?

The default value ("no") will search for pixels inside the range. Pixel values equal to the limits are always marked.

EXAMPLES

1. Print the locations and values of all pixels greater than or equal to 10000 in dev$pix.imh. The first column is the first axis coordinate, and the second column is the second axis coordinate. The third column is the data value at that pixel. Following the command is a sample output from this task.

  im> pixlocate dev$pix 10000 INDEF maxvals=5

  347  188  13988
  348  188  14640
  347  189  19530
  348  189  19936
  347  190  10100

1. Print the coordinates and values of all points having values between 999 and 1000 in the image, with a border of 15 pixels around the axes. Sample output is also shown.

  im> pixlocate foctest$focim6 999 1000 border=15 outside=no

  292   52           999.
  224  124          1000.
  224  125          1000.
  224  126           999.

2. Print the coordinates and values of all negative (or zero) points in the image, ignoring points closer than 10 pixels to the end of any axis. Up to 2000 pixels may be marked in this way.

   im> pixlocate image 0 INDEF maxval=2000 border=10 outside=yes

BUGS

SEE ALSO