Map Area Detection in Image Compression Using Binary and Thin-Line Ratios

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Solution Overview

Problem

Conventional methods for compressing image data struggle to accurately distinguish map areas from other areas, leading to illegible characters in maps during high-compression processes, as they often misclassify areas with similar darkness distribution properties or require extensive processing.

Innovation Solution

A method involving the generation of binary and thin-line images to calculate pixel ratios, determining whether an area is a map or photograph based on these ratios, and applying appropriate compression techniques, including no resolution reduction for maps to maintain legibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high compression rate is applied to map areas, then file size is reduced, but character legibility deteriorates

Engineering Contradiction:
Improvefile sizeVSAvoidcharacter legibility
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies different compression rates to different areas of the image based on their content type. Map areas are identified and compressed at a lower rate to preserve character legibility, while non-map areas are compressed at higher rates. This local differentiation resolves the contradiction by optimizing compression for each region's specific requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent performs preliminary identification of map areas before compression is applied. By detecting map regions in advance using image analysis techniques, the system can pre-determine which areas require legibility preservation, allowing appropriate compression strategies to be applied subsequently without compromising character readability in maps.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If conventional map detection methods are used, then map areas can be identified, but detection accuracy deteriorates due to misclassification of areas with similar darkness distribution

Engineering Contradiction:
Improvemap area identification capabilityVSAvoidmap area detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent changes the detection parameters from simple darkness distribution analysis to a more sophisticated multi-parameter approach. By analyzing additional image characteristics beyond darkness levels, the system can distinguish map areas from other regions with similar darkness properties, thereby improving detection accuracy and reducing misclassification.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If high compression rate is applied to entire image, then file size is reduced, but overall image quality deteriorates

Engineering Contradiction:
Improvefile sizeVSAvoidimage quality
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent implements local quality preservation by identifying specific regions (map areas) that require higher quality retention and applying differentiated compression strategies. Non-map areas receive aggressive compression while map areas are preserved with higher quality, achieving overall file size reduction without compromising important visual information.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS8311333B2Area determination method, image compression method, image compression apparatus, and recording medium
Publication Date: 2012.11.13 KONICA MINOLTA BUSINESS TECH INC
  • US8311333B2 patent drawing
  • US8311333B2 patent drawing
  • US8311333B2 patent drawing

AI summary

First, a binary image is generated by binarizing an image. Next, a binary pixel ratio, that is a ratio of a binary pixel quantity that is a quantity of dotted pixels included in a specific area of the binary image to a total quantity of pixels included in the specific area of the binary image, is found. Then, a thin-line image is generated by performing a line-thinning process on the specific area. After that, a thin-line pixel ratio that is a ratio of the quantity of dotted pixels included in the generated thin-line image to the binary pixel quantity is found, and the specific area is determined to be a map area or a photograph area based on the calculated binary pixel ratio and the calculated thin-line pixel ratio.