Systems and methods for computer recognition of digital speed limit signs using a vehicle onboard camera

A system for computer recognition of road signs using a camera aboard a vehicle, comprising:

• a camera capturing a plurality of image frames including a road sign;
• a computer in data communication with said camera;
• said computer having a sign detection module for identifying a region of interest from each of the image frames, said sign detection module having a detection module for determining a bounding box of the region of interest;
• said computer having a panel extraction module for extracting a portion of the region of interest having light emitting diodes from each of the image frames and outputting a plurality of processed image frames, said panel extraction module having:
• a segment anything module, receiving the bounding box as input, for generating a binary mask relating to the road sign in the image frame;
• an edge detection module, receiving the binary mask as input, for detecting the edges of the road sign in the image frame and outputting the detected edges;
• an inverse perspective mapping module for projecting the region of interest onto an image plane based on the detected edges to produce a projected image frame;
• a cropping module for cropping the projected image frame based on the binary mask to produce a cropped image frame;
• and
• an equalization module inputting the cropped image frame and setting at least a subset of the pixels to a first value and outputting a processed image frame;
• said computer having a multi-frame processing module receiving the plurality of processed image frames as input and for averaging the pixel values of each of the processed image frames, and outputting an average image frame;
• and
• said computer having a classification model for determining a quantum of information displayed on the road sign.

A method for computer recognition of road signs using a camera aboard a vehicle, comprising the steps of:

• providing a camera capturing a plurality of image frames including a road sign;
• providing a computer in data communication with said camera;
• executing a sign detection module on said computer for identifying a region of interest from each of the image frames, including executing a detection module for determining a bounding box of the region of interest;
• executing a panel extraction module for extracting a portion of the region of interest having light emitting diodes from each of the image frames and outputting a plurality of processed image frames, including:
• executing a segment anything module by receiving the bounding box as input and generating a binary mask relating to the road sign in the image frame;
• executing an edge detection module by receiving the binary mask as input and detecting the edges of the road sign in the image frame and outputting the detected edges;
• executing an inverse perspective mapping module for projecting the region of interest onto an image plane based on the edges to produce a projected image frame;
• executing a cropping module for cropping the projected image frame based on the binary mask to produce a cropped image frame;
• executing an equalization module inputting the cropped image frame and setting at least a subset of the pixels to a first value and outputting a processed image frame;
• executing a multi-frame processing module on said computer by receiving the plurality of processed image frames as input and averaging the pixel values of each of the processed image frames, and outputting an average image frame;
• and
• executing a classification model for determining a quantum of information displayed on the road sign.