Color Processing Introduction

Overview

The FIRST Tech Challenge SDK v10.1 software now includes some Color Processing features from OpenCV, a popular and powerful open-source library for vision processing.

Introduced with INTO THE DEEP, these new features will help FIRST Tech Challenge teams identify colors and process color blobs, useful in any game requiring color and shape recognition.

Here’s the outline of this tutorial’s main pages:

• Color Processing Color Sensor
• Color Blob Concepts
• Color Locator (Discover)
• Color Locator (Explore)
• Color Locator (Challenge)
• Color Spaces

Much credit to developer and Sample OpMode author @gearsincorg, EasyOpenCV developer @Windwoes, FTC Blocks developer @lizlooney, and the open-source team at OpenCV.

Compatibility

This new software includes two Color Processors, each compatible with the FTC VisionPortal introduced in 2023. These processors can run alongside an AprilTag processor, and replace the TensorFlow processor (removed in 2024).

These new processors can be used on the usual FTC cameras:

• any UVC-compatible webcam

• the built-in camera of an FTC-supported Android phone (as Robot Controller)

This does not include vision sensors such as HuskyLens and LimeLight 3A, which do not use the FTC VisionPortal.

Two Processors

The new software includes these processors:

• Color Sensor - detects the color of a specified zone in the camera’s view

• Color Locator - gives detailed info on clusters of a specified color, in a specified zone

This tutorial has a Color Sensor page, showing how to use the Sample OpMode called ConceptVisionColorSensor.

For the Color Locator processor, the color “clusters” are called Blobs. As listed above, this tutorial offers one page on Color Blob Concepts, and three pages covering the Sample OpMode called ConceptVisionColorLocator.

The Sample OpModes are available in FTC Blocks, and in Java for use in OnBot Java or Android Studio. Each programming section of this tutorial has a Blocks tab and a Java tab.

Next Steps

Time to get started!

Following this tutorial in order, first try the Sample OpMode for Color Sensor.

Then read about Color Blob Concepts, and try the Color Locator Sample OpMode.

Soon you’ll be ready to add one or both features to your Autonomous OpModes – perhaps even to help automate your TeleOp!

---

Questions, comments and corrections to westsiderobotics@verizon.net