Working with Nodes

A new Imagefilter document is a quite empty window. You only find some status items on the bottom:

• Quality button: (F)ull, (H)alf ad (Q)uarter resolution
  These options allow you to work with subsampled resolution while you design you node-tree.
• Offset-slider
  Allows you to define the image you are working on.
• RAM and File Cache
  Shows you the amount of used RAM or File Cache.

The rest of the interface is up to you. With this program, you will design a node-tree which define the processing of the image. Think of a node as of a black box with one ore more inputs and one output. There are nodes for importing images, for processing the image, for viewing it and for rendering (exporting) it.

You create new nodes from the menus. The new node is drawn as a rectangle with its name. It has three states:

• Normal: gray
• Selected: dark red
• Activated: light red (an activated node is always selected, too)

You can activate a node by clicking on it. You can deactivate the node by clicking outside of the node. You can activate and drag a node immediately. You can select parent and child nodes relative to the activated node to drag them together.

Use the tab key to navigate between nodes (and use shift tag to navigate back).

You can select and deselect nodes with shift-clicking. You can duplicate a group of selected nodes and copy-paste them into a new document.

Nodes are connected at their input and outputs. The inputs are on top and the output is on the bottom. All nodes have an output, but some nodes (importers and generators) do not have inputs. The connectors can have three colors:

• Not connected: transparent
• Connected, but no image available: red
• Connected and image available: green

You can draw connections from an activated node to another node. Click into an input or an output connector and drag to another node. You can drag to the connection of the other node or to the rectangle. If you drag to the rectangle, then it will connect either to the output or to the first input. To remove an input connection, drag a connection outside of the nodes.

Every node has parameters. You can open the parameters with three ways: Double-click the node, pressing the return or the enter key or using the menu Edit:Open Node Editor. The Node Editor appears below the node. You can navigate through the parameters with the mouse or with the up- and down-arrow keys. There are several types of parameters:

• String. Click on it or open it with Enter or Return: A sheet with a textbox appears.
• Checkbox. Click on it or use the left- and right-arrow keys.
• Number. Type the number or use the left- and right-arrow keys. Use option-left and option-right to go faster. Use home and end to go to the minimum and the maximum. You can also click to the optical slider to set the value approximately.
• Color. Click on it or open it with Enter or Return: A window with a color select box opens. You can define the color with one of the menus or use the eyeglass to select a color on screen.
  If the row is selected, you can also control-click anywhere on a pixel in a viewer to sample the color without using the color dialog.
• List. Use the left- and right-arrow keys. Use home and end to go to the first and the last value. Or type the first letter of a value to select it directly. Click or press enter to see the all options of the list.
• File / Folder. Click on it or open it with Enter or Return: A sheet with a file dialog appears.

To leave the node editor, press the escape key or click outside of the editor.