Image filters are used as grey level visual filters superimposed on a spectrum to modify the amplitudes of its components.
AS accepts black and white or colour formats supported by QuickTime : jpg, .pict, .tiff or .pdf.
The image will be superimposed in black and white to the sonogram.
An image can be resized laterally and vertically, on each side. Hover the pointer over a border to display a double triangle , then proceed with a click and drag.
If you wish to resize the image from its upper border, remember that when the image is added in the window, its upper limit will reach the upper limit of the sonogram. This limit can be displayed with a double click on the frequency scale.
The black space left when the image is resized will disappear with a click anywhere in the AS window. It shows that frequencies beyond the image limits will be rejected – see next part.
Like surface filters, images can be moved vertically and horizontally from the Sonogram window and/or Processing Sequencer.