Sheet Edge Detection in Image Processing Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image processing apparatuses face challenges in accurately detecting sheet edges due to image noise, such as reader streaks, which can lead to inaccurate printing position adjustments.
Innovation Solution
An image processing apparatus equipped with a reading device that performs edge detection processing and determines the most likely pair of sheet edges based on detected edge information and sheet size, using techniques like Hough transform and edge detection filters, to robustly detect sheet edges even in noisy conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a reader (ADF) is used to read the sheet, then the reading process can be automated, but image noise such as reader streaks is generated which reduces detection accuracy
Solution Approach 1:
The patent applies this principle by using the reader streak noise pattern itself as a reference to identify and exclude false edge detections. The streak detection unit specifically identifies regions containing reader streaks and excludes them from edge candidate considerations, thereby converting the harmful noise into a detectable pattern that helps improve overall detection accuracy.
Solution Approach 2:
The patent introduces an intermediary processing layer between the raw image reading and edge detection. This includes a streak detection unit and an edge candidate determination unit that act as mediators to filter out noise-induced false positives before final edge detection, thereby protecting the measurement precision while maintaining automation.
2Productivity
If simple edge detection is performed on the read image, then processing is fast and simple, but reader streaks are detected as sheet edges by mistake reducing accuracy
Solution Approach 1:
The patent segments the edge detection process into distinct functional units: a streak detection unit that identifies noise patterns, an edge candidate determination unit that filters candidates based on streak information, and an edge detection unit that performs final detection. This segmentation allows each unit to specialize in one aspect, maintaining overall speed while improving accuracy through coordinated filtering.
Solution Approach 2:
The patent performs preliminary streak detection and candidate filtering before the main edge detection process. By identifying and excluding reader streak regions in advance, the system prevents false positives from entering the main detection pipeline, thereby maintaining high processing speed while ensuring accurate sheet edge detection.
3Adaptability or versatility
If multiple edges are detected without filtering, then all potential edges are captured, but false edges from noise reduce the reliability of printing position adjustment
Solution Approach 1:
The patent implements a feedback mechanism where detected reader streaks are fed back into the edge candidate determination process. The streak detection results are used to adjust and refine the set of edge candidates, continuously improving the reliability of the final edge detection by eliminating false positives while preserving true edges.
Solution Approach 2:
The edge candidate determination unit serves as an intermediary that reconciles the conflict between comprehensive edge capture and reliable edge selection. It uses streak detection information to filter candidates, ensuring that only reliable edges are passed to the final detection stage, thereby maintaining both adaptability and reliability.
Data Source
AI summary
An image processing apparatus having a reading device to read an image from a sheet includes one or more controllers to perform operations. One image is read from one sheet by using the reading device. Edge detection processing is executed on the one image. At least one pair of edges is determined from among a plurality of edges based on information of the plurality of edges detected in the edge detection processing and size information of the one sheet.