Image Resolution Conversion Using Position-Dependent Filter Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing methods fail to achieve accurate output when the resolution conversion ratio is not an integral multiple, leading to biased barycenter and loss of line width uniformity in rendered images.
Innovation Solution
An image processing apparatus and method that determines a pixel of interest in the first image data based on the first and second resolutions, selects appropriate filters, and generates second image data by performing filter processing for the region including the pixel of interest, allowing for high-definition image output even when the resolution conversion ratio is not an integral multiple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If resolution conversion is performed with a non-integral conversion ratio (e.g., 600 dpi to 400 dpi), then the output resolution is achieved, but sampling cannot be executed at an integral ratio causing biased barycenter and loss of line width uniformity
Solution Approach 1:
The patent divides the resolution conversion process into two independent stages: first converting the input image to a intermediate resolution that is an integral multiple of both input and output resolutions, then converting from the intermediate resolution to the final output resolution. This segmentation allows each stage to use integral sampling ratios, avoiding the barycenter bias and line width non-uniformity that occur in direct non-integral conversion.
Solution Approach 2:
The patent introduces an intermediate resolution as a mediator between the input resolution and output resolution. This intermediate resolution serves as a bridge that enables accurate sampling at both conversion stages, preventing the distortion and non-uniformity issues that arise when converting directly between resolutions with non-integral ratios.
2Ease of manufacture
If a single fixed filter is used for resolution conversion, then the processing is simple, but accurate output cannot be obtained when the resolution conversion ratio is not an integral multiple
Solution Approach 1:
The patent dynamically selects different filters based on the position of pixels in the input image. By determining the pixel of interest position and selecting appropriate filters according to positional information, the system adapts the filtering process to maintain accuracy across different conversion scenarios while preserving relative processing simplicity through automated filter selection.
Solution Approach 2:
The patent changes the filter parameters dynamically based on the pixel position and conversion requirements. By selecting from multiple filters with different characteristics according to the specific conversion needs and pixel locations, the system achieves accurate output for non-integral conversion ratios while maintaining efficient processing through parameter-based filter selection.
Data Source
AI summary
An image processing apparatus which generates, from first image data having a first resolution, second image data having a second resolution lower than the first resolution, comprises: a determination unit configured to determine a pixel of interest in the first image data based on the first resolution and the second resolution; a selection unit configured to select one of a plurality of filters in accordance with a position of the pixel of interest in the first image data that has been determined by the determination unit; and a generation unit configured to generate second image data having the second resolution by performing filter processing for a region including the pixel of interest by using the filter selected by the selection unit.