In this tutorial, we stereoize a mono image by applying a different displacement to the red and green channels of an image.  When a displacement map is used, the source image is warped by the displacement map. Where the displacement map is neutral gray, no displacement is made--no matter how hard you try. Black and white pixels in the displacement map warp the source image in opposite directions.

Step 1. Changing the Mono Preset to Stereo

A) Bring the Image Synth window to the front, and open the tutorial presets file. (Shortcut: type 'o' to invoke the Open Presets dialog box).

B) Open the Tutorial7 preset library and press  to choose preset#2 

C) Press the Mono/Stereo toggle . The Stereo image indicator appears 

Step 2. Applying Displacement to Individual Channels

In MetaSynth 2.5, there is a Channel palette which pops up when you click on the channel indicator . It is now possible to restrict all picture manipulations to the red, green and blue channels.

A) Click on the channel indicator , and choose the "red channel only" icon .

B) Choose the Displacement Map :
Double-click the Displacement icon . In the Displacement dialog box, press  and choose . from the popup list. This preset creates nice Gaussian curves.

C) Press  and drag the mouse up or down to displace the red channel. While it is not absolutely necessary to restrict the mouse to only up and down movements, you may find that you get the best results with minimal horizontal displacement. By constraining the displacement to the vertical direction (by pressing the option and shift key), we prevent the rhythm from being modified.

Tip: Horizontal constraint can be obtained by pressing the shift key only.

D) Preview the sound. If you aren't happy with the sound, press 'z' to undo the displacement and try again. Note that when previewing you hear a mono version of the sound. To hear the stereo effect, compute the sound by pressing .

E) Displace the green channel:
Click on the channel indicator, and choose the "green channel only" icon .
Apply a smaller amount of displacement to the green channel. You may want to experiment by selecting another displacement map.

This is our version of the displaced groove:

TIP: When you are done editing the picture, it is a good idea to reselect  from the Channel palette.

F) Press  to compute the sound and press  to add the preset.
 
 

IDEAS FOR FURTHER EXPLORATION:

This technique may yield quite different results with different displacement maps and displacement orientations. Try the different available maps and see what sort of effects you achieve.

Of course, further manipulations may be welcome. Preset #5 was created by succesively applying the Blurr and Pulse Hot Filters with the Grid size at 16. "Smooth right" was applied to yield a decaying envelope before applying "Echo" and "pre-Echo".