Node Categories

The power of PaperVision lies in its organized and color-coded system for building computer vision pipelines. To help you quickly find the specific block of functionality you need, every node is assigned to a distinct category, visually identifiable by its title bar color. Understanding these categories will make building, debugging, and expanding your visual program much faster and more intuitive.

Category Name	Node Color	Purpose	Examples
Pipeline Flow	Cyan	Defines the structural beginning and end of your visual program.	Handling the camera input and outputting the final result.
Image Processing	Orange	The fundamental tools for modifying, enhancing, and preparing an image.	Applying a Threshold, Blur filter, or converting color spaces.
Feature Detection	Indigo	Analyzing the image to find objects, shapes, or points of interest.	Finding the biggest Contour, detecting Blobs, or identifying Bounding Rectangles.
Classification & Filtering	Yellow	Organizing and refining detected objects based on specific criteria.	Filtering contours by area or aspect ratio, or exporting targets.
Drawing & Overlay	Teal	Drawing elements (like shapes or lines) back onto the image for visualization and feedback.	Drawing Contours or Rectangles onto the final output.

Understanding Node Pins and Data Flow

While nodes perform the work, the pins on their edges manage the flow of information. Understanding pin types is essential for building a valid pipeline:

• Inputs (Left Side): These pins accept data from other nodes. A node may have multiple inputs for different types of data (e.g., one for the image, one for a number).

• Outputs (Right Side): These pins release the result of the node's function.

• Data Typing: Every pin is strongly typed and color-coded.

For example, an output pin that provides an image (often with a small image icon) can only be connected to an input pin that is expecting an image. You cannot connect an image output to a numeric input.

If you attempt to link two pins that carry incompatible data types, the connection will not be created, helping you prevent errors in your visual program.