Layers:

Demo
The Layers demo on the following page utilizes the JAI Collections class to store and manipulate a number of images as a group. Operations are typically performed simultaneously on the entire collection. This demo is a simple multi-layered paint program. The top row of buttons are used to select the currently active layer. The left mouse button can be used to paint a free hand path using a small white rectangle. When the mouse is released, the composited result will be shown in the bottom destination window. The sliders are used to contol the percentage of contribution for each layer to the resultant image. This demo is intended to show the basic use of collections and collection operators.

JAI
JAI collections contain rendered or renderable images. They can also contain collections that include collections of images. Some examples of JAI collections include image stacks and image pyramids, often referred to as mip maps.

The AddCollection operation used in this demo takes a collection of rendered images and proportionaly adds them together to form a single output image. See the code for details on the order of operations (multiply individuals then add the group).

Theory
The collection class is primarily a mechanism used to group images together where an operation is applied equally to the entire group.


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