Image Processing Apparatus Frequency Band Enhancement
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Solution Overview
Problem
Existing image processing methods fail to adequately enhance images with fold-over components on the high-frequency side of their frequency spectrum or those lacking sufficient high-frequency components, leading to inappropriate enhancement or noise suppression issues.
Innovation Solution
An image processing apparatus with intermediate image generating and processing means that extract and amplify specific frequency components, using band-pass filters and non-linear processing to add high-frequency components to the input image, preventing overshoot and improving perceived resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-frequency components are enhanced to improve perceived resolution, then image sharpness is improved, but fold-over components are also enhanced causing artifacts
Solution Approach 1:
The patent applies different enhancement strategies to different regions of the frequency spectrum. It identifies and treats fold-over components separately from genuine high-frequency components by analyzing the characteristics of frequency components and applying selective enhancement only to valid high-frequency regions, preventing artifact generation while maintaining sharpness improvement.
Solution Approach 2:
The enhancement process is divided into distinct stages: first identifying fold-over components through frequency analysis, then separating them from genuine high-frequency components, and finally applying enhancement selectively. This segmentation allows the system to improve perceived resolution without enhancing harmful fold-over artifacts.
2Object-generated harmful factors
If frequency band is limited to exclude fold-over components, then artifact generation is prevented, but high-frequency enhancement becomes inadequate
Solution Approach 1:
The patent dynamically adjusts the frequency band parameters for enhancement based on the detected fold-over component locations. Instead of using a fixed frequency cutoff, it modifies the enhancement frequency range to exclude identified fold-over regions while maximizing coverage of genuine high-frequency components, thereby maintaining both artifact prevention and enhancement adequacy.
3Measurement precision
If luminance component is enhanced to improve sharpness, then edge definition is improved, but color accuracy in edge areas deteriorates
Solution Approach 1:
The patent implements dynamic control of enhancement strength based on local image characteristics. It analyzes colorfulness and edge properties at each region and adjusts the enhancement coefficient accordingly, applying stronger enhancement to regions where it benefits sharpness without harming color accuracy, and reducing or eliminating enhancement where color fidelity is critical.
Data Source
AI summary
A first intermediate image generating means (1) generates an intermediate image (D1) by extracting a component of an input image DIN in a particular frequency band; a second intermediate image generating means (2) generates an intermediate image D2 having a frequency component higher than the intermediate image (D1); a first intermediate image processing means (3M) generates an intermediate image (D3M) by amplifying the pixel values in the intermediate image (D1); a second intermediate image processing means (3H) generates an intermediate image (D3H) by amplifying the pixel values in the intermediate image (D2); and an adding means (4) adds the input image (DIN) and the intermediate image (D3M) and the intermediate image (D3H) together to obtain an output image (DOUT). A first amplification factor (D3MA) and a second amplification factor (D3HA) are determined according to pixel values in the input image (DIN). Even if the input image includes a fold-over component on the high-frequency side or does not include an adequate high-frequency component, an enhanced image can be provided without causing overshoot.