This book provides the reader with an understanding of what color is, where color comes from, and how color can be used correctly in many different applications. The authors first treat the physics of light and its interaction with matter at the atomic level, so that the origins of color can be appreciated. The intimate relationship between energy levels, orbital states, and electromagnetic waves helps to explain why diamonds shimmer, rubies are red, and the feathers of the Blue Jay are blue. Then, color theory is explained from its origin to the current state of the art, including image capture and display as well as the practical use of color in disciplines such as computer graphics, computer vision, photography, and film.

Color Imaging: Fundamentals and Applications

An image acquisition sensor of a digital image acquisition apparatus is coupled to imaging optics for acquiring a sequence of images. Images acquired by the sensor are stored. A motion detector causes the sensor to cease capture of an image when the degree of movement in acquiring the image exceeds a threshold. A controller selectively transfers acquired images for storage. A motion extractor determines motion parameters of a selected, stored image. An image re-constructor corrects the selected image with associated motion parameters. A selected plurality of images nominally of the same scene are merged and corrected by the image re-constructor to produce a high quality image of the scene.

Image Acquisition Method and Apparatus

A method of combining image data from multiple frames to enhance one or more parameters of video image quality includes acquiring a first image at a first exposure duration, as well as acquiring a second image at a second exposure duration shorter than the first exposure duration and at a time just before, just after or overlapping in time with acquiring the first image, such that the first and second images include approximately a same first scene. In this way, the second image is relatively sharp and under-exposed, while the first image is relatively well-exposed and less sharp than the second image. Brightness and/or color information are extracted from the first image and applied to the second image to generate an enhanced version of the second image.

Low-light video frame enhancement

An image processing technique includes acquiring a main image of a scene and determining one or more facial regions in the main image. The facial regions are analysed to determine if any of the facial regions includes a defect. A sequence of relatively low resolution images nominally of the same scene is also acquired. One or more sets of low resolution facial regions in the sequence of low resolution images are determined and analysed for defects. Defect free facial regions of a set are combined to provide a high quality defect free facial region. At least a portion of any defective facial regions of the main image are corrected with image information from a corresponding high quality defect free facial region.

Image Processing Method and Apparatus

A large variety of solutions for widening the dynamic range (DR) of CMOS image sensors has been proposed throughout the years. We propose a set of criteria upon which an effective comparative analysis of the performance of wide-DR (WDR) sensors can be done. Sensors for WDR are divided into seven categories: 1) companding sensors; 2) multimode sensors; 3) clipping sensors; 4) frequency-based sensors; 5) time-to-saturation (time-to-first spike) sensors; 6) global-control-over-the-integration-time sensors; and 7) autonomous-control-over-the-integration-time sensors. The comparative analysis for each category is based upon the quantitative assessments of the following parameters: signal-to-noise ratio, DR extension, noise floor, minimal transistor count, and sensitivity. These parameters are assessed using consistent assumptions and definitions, which are common to all WDR sensor categories. The advantages and disadvantages of each category in the sense of power consumption and data rate are discussed qualitatively. The influence of technology advancements on the proposed set of criteria is discussed as well.

Wide-Dynamic-Range CMOS Image Sensors—Comparative Performance Analysis

A wide-dynamic-range CMOS image sensor based on synthesis of one long and multiple short exposure-time signals is proposed. A high-speed, high-resolution column-parallel integration type analog-to-digital converter (ADC) with a nonlinear slope is crucial for this purpose. A prototype wide-dynamic-range CMOS image sensor that captures one long and three short exposure-time signals has been developed using 0.25-mum 1-poly 4-metal CMOS image sensor technology. The dynamic range of the prototype sensor is expanded by a factor of 121.5, compared with the case of a single long exposure time. The maximum DNL of the ADC is 0.3 least significant bits (LSB) for the single-resolution mode and 0.7 LSB for the multiresolution mode

A Wide-Dynamic-Range CMOS Image Sensor Based on Multiple Short Exposure-Time Readout With Multiple-Resolution Column-Parallel ADC

A wide dynamic range CMOS image sensor based on synthesis of long-time and multiple short-time exposure signals for high image quality in the whole illumination range is proposed. A key technique is a high-speed and high-resolution column-parallel integration type analog-to-digital converter (ADC) with nonlinear slope. A prototype wide dynamic range CMOS image sensor that captures a long-exposure and 3 short-exposure signals has been developed with 0.25 /spl mu/m 1-poly 4-metal CMOS image sensor technology. The dynamic range is expanded by a factor of 120 compared with the case of the single long-time exposure. The ADC has a good linearity. The maximum DNL is 0.3 LSB and 0.6 LSB for single- and multi-resolution mode, respectively.

http://ieeexplore.ieee.org/iel5/9624/30805/01426333.pdf

M. Mase

Papers

A Wide-Dynamic-Range CMOS Image Sensor Based on Multiple Short Exposure-Time Readout With Multiple-Resolution Column-Parallel ADC

A wide dynamic range CMOS image sensor with multiple short-time exposures