OCR Accuracy via Video Frame Stacking and Averaging

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Solution Overview

Problem

Optical character recognition (OCR) systems face challenges in accurately extracting text from low-resolution or blurry images of documents, often requiring users to provide additional images, which can be inconvenient and reduce efficiency.

Innovation Solution

The use of video frames captured dynamically from cameras, where OCR systems can extract data from successive frames until text is successfully recognized, adjusting camera settings to improve image quality and combining results from multiple frames for accurate text extraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If OCR systems process low-resolution or blurry images, then text extraction can be attempted, but recognition accuracy deteriorates

Engineering Contradiction:
Improvetext extraction capabilityVSAvoidrecognition accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by capturing multiple video frames before OCR processing. These frames are stacked and averaged to create a high-quality composite image that serves as the input for OCR, enabling accurate text extraction even when individual frames are blurry or low-resolution

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system merges multiple video frames through frame stacking and averaging. By combining information from multiple frames, the system creates a composite image with improved signal-to-noise ratio and enhanced text visibility, resolving the contradiction between processing low-quality images and maintaining recognition accuracy

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If users provide additional images when OCR fails, then text extraction accuracy improves, but operational convenience deteriorates

Engineering Contradiction:
Improvetext extraction accuracyVSAvoiduser convenience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs self-service by automatically capturing and processing multiple video frames without requiring user intervention. The frame stacking and averaging process happens autonomously within the application, eliminating the need for users to manually provide additional images when initial OCR attempts fail

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system maintains continuity of useful action by continuously capturing video frames and processing them through frame stacking until successful text extraction is achieved. This automated continuous process replaces the discontinuous user action of manually providing additional images, improving both accuracy and convenience

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If multiple video frames are processed for OCR, then text recognition accuracy improves, but processing time increases

Engineering Contradiction:
Improvetext recognition accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary frame stacking and averaging before OCR processing, creating a pre-processed composite image that enhances text visibility. This preliminary action reduces the need for multiple iterative OCR attempts, ultimately decreasing total processing time while maintaining high recognition accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The processing is segmented into distinct stages: video frame capture, frame stacking, averaging, and OCR processing. This segmentation allows optimization of each stage independently and enables parallel processing of multiple frames during the stacking phase, reducing overall processing time while achieving high accuracy through combined frame analysis

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3440591B1Improving optical character recognition (OCR) accuracy by combining results across video frames
Publication Date: 2022.10.12 INTUIT INC
  • EP3440591B1 patent drawingFigure 1
  • EP3440591B1 patent drawingFigure 2
  • EP3440591B1 patent drawingFigure 3

AI summary

The present disclosure relates to optical character recognition using captured video. According to one embodiment, using a first image in stream of images depicting a document, the device extracts text data in a portion of the document depicted in the first image and determines a first confidence level regarding an accuracy of the extracted text data. If the first confidence level satisfies a threshold value, the device saves the extracted text data as recognized content of the source document. Otherwise, the device extracts the text data from the portion of the document as depicted in one or more second images in the stream and determines a second confidence level for the text data extracted from each second image until identifying one of the second images where the second confidence level associated with the text data extracted from the identified second image satisfies the threshold value.