Configuring Color Signatures in VEXcode AIM – VEX Library

A Color Signature is one of the two types of Visual Signatures utilized by the AI Vision Sensor in the VEX AIM Coding Robot for color identification. To enable the AI Vision Sensor to recognize Color Signatures, they need to be configured initially. Follow the steps outlined in this article to properly configure Color Signatures.

Note: A wired connection must be used to use the AI Vision Utility and configure color signatures for the robot. See this article to learn more about connecting an robot to VEXcode AIM using a wired connection.

Configure a Color Signature

AI Vision Utility in VEXcode AIM. The left shows the camera feed from the robot with a red cube in the center of a white background.

Put what solid-colored object you want the AI Vision Sensor to be able to recognize in front of it.

Position your mouse cursor over the solid-colored object, then select and drag across the desired color to configure it. A red box will appear across the edge of the area that was selected.

Note: Make sure to stay within the confines of the color you want to select. Otherwise, you may accidentally grab colors from the background that can throw off the AI Vision Sensor’s detection.

Same Utility as before with a red box on the red cube, showing where the color was selected. On the right side of the window the Set Color button is highlighted.

The Set Color button will become available. Select it to save the color.

Once a color is set, the AI Vision Sensor will save it as a Color Signature.

Zoomed in version of the AI Vision utility window with a callout on the Name text box of the color signature that was just set.

Rename the color signature by selecting into the Name textbox and typing.

AI Vision Utility Window zoomed in on the right side with a highlight on the add color button.

Select Add Color to configure any further Color Signatures for other objects.

The AI Vision Sensor can track up to 7 Color Signatures at a time.

AI Vision Utility in VEXcode AIM with a highlight on the close button in the bottom right corner.

Once all desired colors have been set, select Close.

Zoomed in view of the Control Panel in VEXcode AIM with a highlight around the Configured Colors section. Within is a row that matches the color previously configured.

All configured color signatures will now appear in the AIM Control Panel.

Tune a Color Signature

Color Signatures can have their Hue Range and Saturation Range tweaked so the sensor can detect the color easier.

Zoomed in view of the AI Vision Utility that shows the options available for tuning the set color signature.

When configuring a color signature, options appear for both Hue and Saturation Ranges. These allow you to tune the color signature to be more resilient. A color signature is considered resilient when the object can be moved around and still be tracked by the AI Vision Utility.

Circle with cascading rainbow colors. Red is at the 0 degree heading, green is at approximately the 120 degree heading, and blue is at approximately the 240 degree heading.

The first slider is the Hue Range. Hue is the color perceived, as defined by its position on the color wheel. This color wheel has a range of 0 to 359.9 degrees and each color on the wheel has a defined degree value.

The Hue Range allows you to choose the degrees above and below the configured color that will report as that color. For example, a dark blue may have the hue value of 240 degrees. With a Hue Range of 20 degrees, anything from 220 degrees to 260 degrees will report as that dark blue configured color.

To tune your color configuration, slowly move the Hue Range slider until the target box is stable around the object. Do not move it any further than it needs to.

Table showing the change of colors based on saturation values. At the furthest left equal to 0% saturation, the color appears grey. The brightness of the color increases as you move to the right and see increases in saturation values.

The second slider is the Saturation Range. Saturation is the intensity or purity of the color. The brighter the color, the more saturated it is. Saturation is a relative scale measured with percentages from 0%, being a muted grey tone, and 100% being a intense version of that hue.

The Saturation Range allows you to choose the percent of saturation above and below the configured color that will report as that color. For example, a red ball in dimmer lighting may appear as 50% saturation. With a Saturation Range of .25 (the decimal equivalent of 25%), anything from 25% to 75% saturation will report as that red configured color.

Move the slider for the Saturation Range until the object you want to track is fully surrounded by the target box.

Now you can test the resiliency of your Color Signature. Put the object in different lighting conditions or move it around to see if the AI Vision Sensor can continue to track it in different settings and conditions.

Once two or more Color Signatures have been set, you can begin to configure Color Codes.