TVBOX: Draw a Box on the Image Display

Form: TVBOX [BOX=b] [SIZE=s PIX=r,c]
BOX=b
tells the program to show the bounds of box 'b' on the television.
SIZE=s PIX=r,c
draws a box of size 's' centered at row 'r' and column 'c'

TVBOX is used to show the boundaries of a box on the television. You can show a box defined in the command BOX, or show a region centered on a given point. You must specify EITHER the box number with BOX=, or the size AND the location with SIZE= and PIX=.

There must be an image already in the TV for this command to work. The displayed box will be clipped at the edge of the image if the box extends over the bounds of the image.

Examples:

TVBOX BOX=3
display the boundaries of box 3 on the television.
TVBOX SIZE=51 PIX=123,234
display a box of size 51 pixels, centered at row 123 and column 234.