Image Processing Device Tone Value Downsampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image data transmission from image generating devices to printing apparatuses is inefficient due to the lack of consideration for downsizing data volume, leading to longer transmission times.
Innovation Solution
An image processing device that downscales tone values of pixels and assigns shorter codes to frequently occurring values, using a halftoning process and entropy coding to generate coded image data, which is then transmitted to a printing apparatus for efficient data reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If image data is transmitted without downsizing, then transmission accuracy is maintained, but transmission time increases
Solution Approach 1:
The patent applies entropy coding to change the parameter representation of image data. By assigning variable-length codes based on frequency distribution (shorter codes for frequent values, longer codes for rare values), the data volume is reduced while maintaining transmission accuracy. This parameter transformation enables faster transmission without losing image information.
2Productivity
If uniform code lengths are assigned to all tone values, then encoding simplicity is maintained, but data compression efficiency decreases
Solution Approach 1:
The patent implements local quality by assigning different code lengths to different tone values based on their frequency distribution. Frequently occurring tone values receive shorter codes while rare values receive longer codes. This localized optimization of code length for each tone value improves overall compression efficiency without requiring complex adaptive algorithms.
3Productivity
If frequency analysis of entire pages is performed, then optimal code assignment is achieved, but processing complexity increases
Solution Approach 1:
The patent applies partial action by performing frequency analysis on a sample basis rather than analyzing every pixel in the entire image. This partial analysis provides sufficient information to determine optimal code assignments for tone values, achieving good compression ratios without the excessive processing complexity of complete page analysis.
Data Source
AI summary
An image processing device to generate coded image data, which represents an image to be printed in a printing apparatus, is provided. The image processing device includes a data generator to downscale tone values of pixels included in the image, the tone values of pixels being included in a predetermined scale range, and assign a plurality of types of codes having different lengths to the downscaled tone values to generate image data, and a data transmitter configured to transmit the coded image data to the printing apparatus. The data generator downscales the tone values of pixels by classifying each tone value of pixels into one of segments, which are unevenly delimited by predetermined thresholds within the predetermined scale range and include a larger segment and a smaller segment, and assigning a code with a shorter bit length to the tone value classified into the larger segment.