Autoencoder-Based Appearance Defect Detection for Image Detail Preservation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for detecting appearance defects in products suffer from reduced accuracy due to image zooming, which alters pixel numbers and leads to loss of image details.

Innovation Solution

The method involves obtaining positive and negative sample images, dividing product sample images into input blocks, and processing these blocks through a pre-trained autoencoder to reconstruct images without zooming, thereby maintaining image detail and improving detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If image zooming is applied to detect appearance defects, then the detection coverage is improved, but the image detail quality deteriorates due to pixel number changes

Engineering Contradiction:
Improvedetection coverageVSAvoidimage detail quality
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent divides the product image into multiple image blocks and processes each block separately through the autoencoder. This segmentation allows the system to maintain original image resolution while covering the entire product surface, resolving the contradiction between detection coverage and image detail quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses an autoencoder to create a reconstructed copy of the input image block. By comparing the original image block with its reconstructed copy, the system can detect defects without altering the original image resolution, thus maintaining image detail quality while achieving comprehensive detection coverage.

Inventive Principle:
Principle #26Copying

2Productivity

If traditional defect detection methods are used, then the processing speed is maintained, but the detection accuracy deteriorates due to image detail loss

Engineering Contradiction:
Improveprocessing speedVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent pre-trains the autoencoder model using normal product images before actual defect detection. This preliminary action enables the model to learn normal product features in advance, so during detection it can quickly compare actual images against the learned normal patterns, achieving both high processing speed and high detection accuracy without losing image details.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS12315128B2Method for detecting appearance defects of a product and electronic device
Publication Date: 2025.05.27 HON HAI PRECISION INDUSTRY CO LTD
  • US12315128B2 patent drawing
  • US12315128B2 patent drawing
  • US12315128B2 patent drawing

AI summary

A method for detecting defects in appearance of a product from images thereof, applied in an electronic device, obtains positive sample images, negative sample images, and product sample images, divides the product sample images into input image blocks, and inputs the input image blocks into a pre-trained autoencoder to obtain reconstructed image blocks. The electronic device determines corresponding pixel points in the input image blocks, and corresponding pixel difference values, and generates feature connection regions of each input image block according to the positive sample images and the pixel difference values. The electronic device generates a first threshold, selects target regions from the feature connection regions and the first threshold, and generates a second threshold. The electronic device further determines a detection result of a product sample in the product sample image according to an area of the target area and the second threshold.