Image Orientation Detection Using Shape Pattern Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing techniques are limited in determining the correct orientation of images with various subjects and compositions, as they rely on color features and face alignment, which are not robust to light source environments and are applicable only to images with multiple people captured side by side.
Innovation Solution
An image processing device and method that detects objects by pattern matching between an image and a reference image while changing the relative angle, identifying the top and bottom of the image to determine its correct orientation, and updates the image data for proper display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If skin area detection and alignment-based orientation determination is used, then the vertical direction can be determined for images with multiple people, but the method is weak in robustness to light source environment, color of clothes, and positions of arms and legs
Solution Approach 1:
The patent changes the detection parameter from color-based skin area detection to shape-based pattern matching. By using template matching with predefined object shapes (faces, bodies, objects) and comparing geometric patterns rather than color features, the method achieves robustness against variations in lighting conditions, clothing colors, and body positions while maintaining applicability to diverse image content.
2Measurement precision
If face alignment-based orientation determination is used, then the vertical direction can be determined, but it is assumed that a plurality of people are being captured side by side, thus limiting applicability
Solution Approach 1:
The patent creates a universal orientation determination system that can handle multiple types of subjects (people, objects, landscapes) through a single pattern matching framework. By defining multiple template patterns for different object types and using shape-based rather than face-specific detection, the system achieves multi-functionality across diverse image content while maintaining precise orientation determination through the identified object's alignment.
3Adaptability or versatility
If pattern matching with angle changing is performed, then objects can be detected in various orientations, but the processing time increases
Solution Approach 1:
The patent applies partial action by performing pattern matching at selectively chosen angles rather than exhaustively testing all possible orientations. The system rotates the image or template at discrete angle intervals (e.g., 0°, 45°, 90°, 135°) to detect object orientation, achieving sufficient adaptability for various orientations while significantly reducing processing time compared to continuous angle scanning.
Data Source
AI summary
A face detection processing unit performs a face detection process by rotating an image in increments of a predetermined angle and acquires a rotation angle at which a face is detected. An angle correction unit acquires an angle between the face and a shoulder by pattern matching and corrects the rotation angle of the image. A human-image orientation identification unit identifies a correct orientation of a human image based on the rotation angle. An image-characteristic analysis unit analyzes a frequency distribution and a brightness distribution of a non-human image. A non-human image orientation identification unit identifies the correct orientation of a non-human image based on distribution characteristics of a frequency of brightness with respect to an axis in a predetermined direction. An image-data updating unit incorporates information regarding the correct orientation in the image data.