Holographic Data Image Sub-Pixel Distortion Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Holographic systems face challenges in precisely compensating distortions in data images reproduced from storage media, particularly at the half-pixel level, which affects the quality of the data image.
Innovation Solution
An apparatus and method that preprocesses page images by calculating pixel sums, determining modified border locations through curve fitting, and adjusting over-sampling based on distortion errors to compensate for pixel distortions, allowing for sub-pixel level corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional border detection method is used to determine data image boundaries, then border locations can be identified, but pixel distortion compensation precision is limited to integer pixel levels
Solution Approach 1:
The patent transitions from integer pixel-level border detection to sub-pixel level precision by introducing fractional pixel coordinates. The border location is determined not just at discrete pixel centers but at continuous coordinate positions between pixels, enabling distortion compensation with precision finer than one pixel. This dimensional extension from discrete to continuous space resolves the contradiction between detection capability and compensation precision.
Solution Approach 2:
The patent changes the parameter of border location from integer pixel coordinates to real-valued sub-pixel coordinates. By allowing border positions to be expressed as fractional values (e.g., 140.3 pixels rather than just 140 pixels), the system achieves higher precision in both detecting border locations and subsequently compensating for pixel distortions during over-sampling operations.
2Productivity
If over-sampling is performed based on detected border locations, then data image can be extracted, but pixel distortion remains uncorrected affecting image quality
Solution Approach 1:
The patent performs preliminary distortion compensation by calculating correction factors based on sub-pixel border locations before executing the over-sampling process. The system determines the exact border position with sub-pixel precision, computes the necessary pixel shift corrections in advance, and then applies these corrections during data extraction. This preliminary action ensures that pixel distortions are corrected proactively rather than requiring post-processing, thereby maintaining both extraction efficiency and image quality.
Data Source
AI summary
The present invention provides a method and apparatus for preprocessing a page image reproduced from a storage medium in a holographic system. The present invention calculates pixel sums for each lines in the page image to select a maximum sum, calculates a modified maximum sum using the modified maximum sum and its neighboring sums, determines a compensation location for distorted pixels using the modified maximum sum and performs over-sampling a data image with reference to the compensation location of magnified pixels, to thereby compensate the data image with high precision in sub-pixels.