Sony DCR-TRV39 - Manual (Page 200)

Stencil masks
Stencil masks
Available stencil masks are listed here.
[OK] button
Click to apply the selected stencil mask.
Drawn masks
After selecting a tool, use the mouse to draw your
custom mask directly on the image in the editor window.
Changes will be applied upon returning to the layout
environment.
Brush button
Click to draw a custom mask with the brush.
Pen button
Click to draw a custom mask with the pen.
Eraser button
Click to erase portions of the custom mask currently being drawn.
Paint button
Click to apply a mask to the entire picture.