Show-through removal switching for halftone dot detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional show-through removal methods in image forming apparatuses are ineffective when there is no halftone dot region in the image data, leading to degradation in image quality, as they rely on variance values within halftone dot regions, which are not applicable to images without such regions, such as photographic paper or error diffusion originals.
Innovation Solution
An image processing apparatus that determines the presence or absence of a halftone dot region by calculating variance values and switching between a first removal process for images with halftone dots and a second removal process without them, using a threshold value to differentiate and apply appropriate show-through removal techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a show-through removal process based on variance values of halftone dot regions is used, then show-through can be effectively removed from images with halftone dots, but the process becomes ineffective and degrades image quality when applied to images without halftone dot regions
Solution Approach 1:
The patent changes the processing parameters based on the detected image type. For halftone dot images, it uses variance value-based show-through removal with halftone dot region detection. For non-halftone images (photographic, error diffusion), it switches to a different processing approach that does not rely on halftone dot characteristics, thereby adapting the parameters to match the image characteristics and avoiding quality degradation
Solution Approach 2:
The patent introduces dynamic switching between different show-through removal processes based on image type detection. The system dynamically adjusts the processing method by first detecting whether the image contains halftone dots, then selecting the appropriate removal algorithm, making the system adaptable rather than static
2Ease of manufacture
If a fixed show-through removal algorithm is applied to all images, then the process is simple to implement, but it cannot handle diverse image types effectively leading to quality loss
Solution Approach 1:
The patent segments the image processing task into two distinct paths based on image type detection. It divides all images into halftone dot images and non-halftone images, then applies specialized processing to each segment. This segmentation allows each processing path to be optimized for its specific image type while maintaining overall system simplicity through clear conditional logic
Data Source
AI summary
An image processing apparatus according to embodiments obtains a variance value of signal values of pixels included in a predetermined region of the read image read from an original, and compares the obtained variance value with a threshold value for determining whether the read image has a halftone dot region. Furthermore, the present image processing apparatus, upon determining that the read image includes a halftone dot region in accordance with the result of this comparison, executes a first removal process for removing the reflection of an image of one surface of an original when reading the other surface, and executes a second removal process otherwise.