Programmable Lookup Table for CMOS Image Sensor Processing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional CMOS image sensors require substantial redesign and increased complexity to add new image processing functions, leading to longer design cycles and higher costs due to the need for dedicated logic circuitry and memory allocation for each function.

Innovation Solution

A system-on-chip digital image sensor with a multi-functional programmable lookup table that allows for dynamic programming of image processing functions, such as dead pixel correction, CDS subtraction, and privacy masking, without the need for re-design, using a processing unit and data memory to interpret pixel codewords and generate output image data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dedicated logic circuitry and memory allocation are added for each image processing function, then the image processing capability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improveimage processing capabilityVSAvoidlogic circuitry complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal image processing function through a programmable lookup table that can be configured to perform multiple different image processing operations (such as dead pixel correction, CDS subtraction, privacy masking) without requiring separate dedicated logic circuitry for each function. This allows a single hardware structure to serve multiple purposes, reducing overall device complexity while maintaining versatile image processing capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent changes the operational parameters of a fixed hardware structure (lookup table) through software programming to achieve different image processing functions. By reprogramming the lookup table with different data or lookup tables, the same hardware can perform various processing tasks without physical modification, thereby reducing device complexity while improving adaptability.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If dedicated logic circuitry is added for each image processing function, then the image processing capability is improved, but the manufacturing cost increases

Engineering Contradiction:

Improveimage processing capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If new image processing functions are added through redesign, then the image processing capability is improved, but the design cycle time increases

Engineering Contradiction:

Improveimage processing capabilityVSAvoiddesign cycle time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements dynamic functionality by allowing the lookup table to be reprogrammed after manufacturing to adapt to different image processing requirements. This dynamic reconfiguration capability eliminates the need for time-consuming hardware redesign when new processing functions are needed, as the same hardware can be software-updated to perform new tasks.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

Inventive Principle:

Principle #35Parameter changes

4Adaptability or versatility

If extensive re-design is performed to add image processing functions, then the image processing capability is improved, but the implementation complexity increases

Engineering Contradiction:

Improveimage processing capabilityVSAvoidimplementation complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses a lookup table that stores pre-computed processing data or lookup operations. Instead of implementing complex processing algorithms through dedicated logic circuitry, the system copies and retrieves pre-processed data from the lookup table, simplifying the implementation complexity while maintaining versatile image processing capability.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS7362355B1Digital CMOS image sensor incorporating a programmable multi-functional lookup table

Publication Date: 2008.04.22 PIXIM INC

AI summary

A system-on-chip imaging system includes an image sensor of a two-dimensional array of pixel elements providing pixel data representing an image of a scene, a data memory for storing pixel codewords whereby at least some of the pixel codewords are indicative of the pixel data, a programmable lookup table for providing LUT codewords as output data, and a processing unit for receiving LUT codewords from the lookup table and generating output image data. In operation, a first pixel codeword stored in the data memory is used to index the lookup table for causing the lookup table to provide a respective LUT codeword to the processing unit. The processing unit operates to perform one or more image processing functions in response to the LUT codeword. The lookup table can be programmed to perform a variety of image processing functions, including defective pixel correction, CDS subtraction, privacy masking and dark signal subtraction.