CONTRAST

CONTRAST N,V

CHANGES THE CONTRAST OF THE SYSTEM OBJECT NUMBER N (PICTURE)

  • Type: Command
  • Parameters: 2
  • Group: System Objects

ACTION

The command CONTRAST N,V changes the contrast of the system object, designated by its number N. The system object is a PICTURE.

Every time The command is executed:

- if V=0, the picture remains unchanged,

- if V<0, its contrast decreases,

- if V>0, its contrast increases.

Remark : V must be between -128 and 127.

SYNTAX: CONTRAST N,V

  • N = system object number (integer or real). Must be greater than 0 and less than or equal to the allowed maximum number of system objects.
  • V = contrast value.

USE

  • The command CONTRAST is used to change the contrast of a PICTURE.

ERROR

  • If number N is not a correct expression.
  • If number N exceeds the allowed maximum number of system objects.
  • If number N is less than 0.
  • If system object number N does not exist.
  • If system object of number N is not of type PICTURE.
  • If V is less than -128 or greater than 127.
  • If V is not a correct expression.

EXAMPLE

rem create an object PICTURE

picture 1

rem load a picture

file_load 1,"my_picture.bmp"

rem increase its contrast

contrast 1,10

SEE ALSO

PICTURE

BRIGHTNESS

GAMMA