Image Processing for Copy-Forgery-Inhibited Pattern Data Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional printers face challenges in reducing the data size of copy-forgery-inhibited pattern image data after compression while maintaining image quality, particularly for black and chromatic color images, as JPEG compression results in large data sizes and image degradation.
Innovation Solution
An image processing apparatus that determines the color space for compressing image data, concentrating AC components on a specific plane to reduce data size without degrading image quality, by using a color determiner, color space determiner, and converter to convert and compress image data in either the RGB or YCbCr color space based on the identified color characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If JPEG compression is applied to copy-forgery-inhibited pattern image data, then the data size is reduced, but the image quality degrades and data size remains large for black and chromatic color images
Solution Approach 1:
The patent changes the color space parameter from RGB to YCbCr for chromatic color images and to grayscale for black images. This parameter transformation allows the image data to be compressed more efficiently while maintaining visual quality, as the human eye is more sensitive to luminance changes than color changes. The YCbCr color space separates luminance (Y) from chrominance (Cb, Cr), enabling selective compression of color information.
Solution Approach 2:
The patent applies different compression strategies to different parts of the image data based on its characteristics. For black images, grayscale compression is applied; for chromatic color images, YCbCr color space transformation followed by selective chrominance subsampling is applied. This local adaptation of compression parameters optimizes both data size reduction and quality preservation for different image types.
2Device complexity
If conventional JPEG compression is used on black color copy-forgery-inhibited pattern images, then the compression process is simple, but the data size after compression remains large
Solution Approach 1:
The patent transforms black color images from RGB to grayscale parameter space before compression. This single parameter change (from 3 color channels to 1 luminance channel) dramatically reduces the data volume while maintaining the essential visual information. The grayscale conversion is computationally simple yet highly effective for reducing compressed data size of black images.
3Quantity of substance
If JPEG compression is applied to chromatic color copy-forgery-inhibited pattern images, then the compression is performed, but the data size remains large and hue degradation occurs
Solution Approach 1:
The patent transforms chromatic color images from RGB to YCbCr color space parameters. This transformation separates the image into luminance (Y) and chrominance (Cb, Cr) components. The human visual system is less sensitive to chrominance changes, allowing for effective compression of the Cb and Cr channels while preserving the Y channel at higher quality, thus reducing overall data size while minimizing perceived hue degradation.
Solution Approach 2:
The patent uses a composite approach by combining different compression strategies for different components of the image data. The luminance component is compressed with higher fidelity while the chrominance components are compressed with lower fidelity. This composite compression strategy leverages the psychovisual properties of human color perception to achieve better overall compression efficiency.
Data Source
AI summary
According to the claimed invention, an image processing apparatus is provided, wherein the image processing apparatus comprises a color determiner, adapted to determine a color of image data; a color space determiner, adapted to determine a color space for compressing the image data based on the color determined by the color determiner; and a converter, adapted to convert the image data into data on a plurality of planes that constitute the color space determined by the color space determiner and compressing the data on each plane, wherein the color space determiner determines the color space based on the color determined by the color determiner so that AC components of the image data concentrate on a certain plane of the plurality of planes.