An image guide file is a text file containing one or more drawing commands which describe guides to overlay on compositing images.
In a compositing viewer pane, open the right side toolbar and click Display Options or press D to open the Display Options window.
Click the Viewport tab.
Use the Image Guide option to set the image guide file to use.
All coordinates are expressed in pixels.
Sets the drawing color.
Draws a box at (X,Y) with the specified Width and Height.
Draws a box with one corner at (X1, Y1) and the opposite corner at (X2, Y2).
Draws a line from (X1, Y1) to (X2, Y2).
Draws N lines from (X1, Y1) to (X2, Y2), offsetting both coordinate pairs by ( dX, dY) each time. Use this to draw grids.