RDPIX Procedure

Standard Library procedure that displays the x, y, and pixel values at the location of the cursor in the image displayed in the currently active window.

RDPIX, image [, x0, y0]

image The image array loaded into the current window. May be any type. Pixel values are read from within the borders of the image; they are not read in relation to the full display area of the screen. This avoids scaling difficulties.

x0 The x-coordinate of the lower-left corner of the image displayed in the currently active window.

y0 The y-coordinate of the lower-left corner of the image displayed in the currently active window.

None.

The x, y, and pixel values under the cursor position are constantly displayed and updated. Pressing the left or center button makes a new line of output, saving the old line on the display. Pressing the right mouse button exits the procedure.

OPENR, lun, !Data_dir + 'mandril.img', /Get_lun
mandril_img = BYTARR(512, 512)
READU, lun, mandril

; Read in the image file.

TV, mandril_img

; Display the image.

RDPIX, mandril_img

; Press the left or center mouse button to see pixel values, and the
; right mouse button to quit.

TV, mandril_img, 100, 100

; Display the image offset on the screen by 100 pixels vertically and
; horizontally.

RDPIX, mandril_img, 100, 100

; Read the pixel values from the offset image. Then press the left or
; center mouse button to see pixel values, and right mouse button to
; quit.

CURSOR