Optical image compression and encryption methods

International audienceOver the years extensive studies have been carried out to apply coherent optics methods in real-time communications and image transmission. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. However, the transmitted data can be intercepted by nonauthorized people. This explains why considerable effort is being devoted at the current time to data encryption and secure transmission. In addition, only a small part of the overall information is really useful for many applications. Consequently, applications can tolerate information compression that requires important processing when the transmission bit rate is taken into account. To enable efficient and secure information exchange, it is often necessary to reduce the amount of transmitted information. In this context, much work has been undertaken using the principle of coherent optics filtering for selecting relevant information and encrypting it. Compression and encryption operations are often carried out separately, although they are strongly related and can influence each other. Optical processing methodologies, based on filtering, are described that are applicable to transmission and/or data storage. Finally, the advantages and limitations of a set of optical compression and encryption methods are discussed

BCR’s CDP Digital Imaging Best Practices, Version 2.0

This is the published version.These Best Practices — also referred to as the CDP Best Practices -- have been created through the collaboration of working groups pulled from library, museum and archive practitioners. Version 1 was created through funding from the Institute for Museum and Library Services through a grant to the University of Denver and the Colorado Digitization Program in 2003. Version 2 of the guidelines were published by BCR in 2008 and represents a significant update of practices under the leadership of their CDP Digital Imaging Best Practices Working Group. The intent has been to help standardize and share protocols governing the implementation of digital projects. The result of these collaborations is a set of best practice documents that cover issues such as digital imaging, Dublin Core metadata and digital audio. These best practice documents are intended to help with the design and implementation of digitization projects. Because they were collaboratively designed by experts in the field, you can be certain they include the best possible information, in addition to having been field tested and proven in practice. These best practice documents are an ongoing collaborative project, and LYRASIS will add information and new documents as they are developed

Digital Color Imaging

This paper surveys current technology and research in the area of digital color imaging. In order to establish the background and lay down terminology, fundamental concepts of color perception and measurement are first presented us-ing vector-space notation and terminology. Present-day color recording and reproduction systems are reviewed along with the common mathematical models used for representing these devices. Algorithms for processing color images for display and communication are surveyed, and a forecast of research trends is attempted. An extensive bibliography is provided

Joint Optimization of Low-power DCT Architecture and Effcient Quantization Technique for Embedded Image Compression

International audienceThe Discrete Cosine Transform (DCT)-based image com- pression is widely used in today's communication systems. Signi cant research devoted to this domain has demonstrated that the optical com- pression methods can o er a higher speed but su er from bad image quality and a growing complexity. To meet the challenges of higher im- age quality and high speed processing, in this chapter, we present a joint system for DCT-based image compression by combining a VLSI archi- tecture of the DCT algorithm and an e cient quantization technique. Our approach is, rstly, based on a new granularity method in order to take advantage of the adjacent pixel correlation of the input blocks and to improve the visual quality of the reconstructed image. Second, a new architecture based on the Canonical Signed Digit and a novel Common Subexpression Elimination technique is proposed to replace the constant multipliers. Finally, a recon gurable quantization method is presented to e ectively save the computational complexity. Experimental results obtained with a prototype based on FPGA implementation and com- parisons with existing works corroborate the validity of the proposed optimizations in terms of power reduction, speed increase, silicon area saving and PSNR improvement

Prioritizing Content of Interest in Multimedia Data Compression

Image and video compression techniques make data transmission and storage in digital multimedia systems more efficient and feasible for the system's limited storage and bandwidth. Many generic image and video compression techniques such as JPEG and H.264/AVC have been standardized and are now widely adopted. Despite their great success, we observe that these standard compression techniques are not the best solution for data compression in special types of multimedia systems such as microscopy videos and low-power wireless broadcast systems. In these application-specific systems where the content of interest in the multimedia data is known and well-defined, we should re-think the design of a data compression pipeline. We hypothesize that by identifying and prioritizing multimedia data's content of interest, new compression methods can be invented that are far more effective than standard techniques. In this dissertation, a set of new data compression methods based on the idea of prioritizing the content of interest has been proposed for three different kinds of multimedia systems. I will show that the key to designing efficient compression techniques in these three cases is to prioritize the content of interest in the data. The definition of the content of interest of multimedia data depends on the application. First, I show that for microscopy videos, the content of interest is defined as the spatial regions in the video frame with pixels that don't only contain noise. Keeping data in those regions with high quality and throwing out other information yields to a novel microscopy video compression technique. Second, I show that for a Bluetooth low energy beacon based system, practical multimedia data storage and transmission is possible by prioritizing content of interest. I designed custom image compression techniques that preserve edges in a binary image, or foreground regions of a color image of indoor or outdoor objects. Last, I present a new indoor Bluetooth low energy beacon based augmented reality system that integrates a 3D moving object compression method that prioritizes the content of interest.Doctor of Philosoph

From Sophisticated Analysis to Colorimetric Determination: Smartphone Spectrometers and Colorimetry

Smartphone-based spectrometer and colorimetry have been gaining relevance due to the widespread advances of devices with increasing computational power, their relatively low cost and portable designs with user-friendly interfaces, and their compatibility with data acquisition and processing for “lab-on-a-chip” systems. They find applications in interdisciplinary fields, including but not limited to medical science, water monitoring, agriculture, and chemical and biological sensing. However, spectrometer and colorimetry designs are challenging tasks in real-life scenarios as several distinctive issues influence the quantitative evaluation process, such as ambient light conditions and device independence. Several approaches have been proposed to overcome the aforementioned challenges and to enhance the performance of smartphone-based colorimetric analysis. This chapter aims at providing researchers with a state-of-the-art overview of smartphone-based spectrometer and colorimetry, which includes hardware designs with 3D printers and sensors and software designs with image processing algorithms and smartphone applications. In addition, assay preparation to mimic the real-life testing environments and performance metrics for quantitative evaluation of proposed designs are presented with the list of new and future trends in this field

Computer Graphics and Visualization based Analysis and Record System for Hand Surgery and Therapy Practice

In this thesis, we have designed and developed a computer graphics and visualization based analysis and record system for hand surgery and therapy practice. In particular, we have designed and developed three novel technologies: (i) model-based data compression for hand motion records (ii) model-based surface area estimation of a human hand and (iii) an emulated study of hand wound area estimation. First, we have presented a new data compression technique to better address the needs of electronic health record systems, such as file storage and privacy. In our proposed approach, we will extract the patient\u27s hand motion information and store the motion data in a binary format, and then we use a loss less data compression to further reduce the file size. To illustrate this idea, we have built a prototype, which demonstrates our entire work flow. Our experiment results have shown the effective compression performance as well as added benefit of 3-D review, enhanced privacy and review capability at different playback speeds and view angles. Next, we developed a new approach, to estimate the surface area of a patient\u27s hand accurately and quickly with a low-cost imaging sensor and a graphics based hand model. Through the image capturing device, we capture infrared images of the patient\u27s hand. Once we get the input images, we run them through the image analysis engine to extract the required information in order to obtain a customized graphics hand object. Once customized we use the graphics hand object to calculate the surface area of the patient\u27s hand. To illustrate this idea, we have built a prototype system, which demonstrate the entire work flow. Our experiment results have shown considerable reproducibility and consistency. Finally, we came up with a novel system, capable of identifying simulated wounds on a human hand and estimating their area. Through the imaging device, wound analysis engines, we are able to identify simulated wounds on a patient\u27s hand and measure their area using optical equations. To illustrate this idea, we have built a prototype system, which demonstrates our entire work flow. Our experiments show considerable reproducibility, accuracy and consistency. In summary, we have developed prototypes for each of the approaches to demonstrate its capabilities. Experiments and analysis are carried out to study their performance and complexity. We believe these new approaches can significantly improve the current practice in hand surgery analysis and therapy practice

Benchmarking of mobile phone cameras

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A Comparison study of the implementation of digital camera’s RAW and JPEG and scanner’s TIFF file formats, and color management procedures for inkjet textile printing applications

The objective of this research was to evaluate the results and characteristics of utilizing different image file formats in inkjet textile printing. Two format files derived from digital camera (JPEG and RAW format files) and two TIFF format files derived from scanning the transparency films were sent through color management processes and adjustment procedures. These images files were then rendered on 100% cotton fabric using an inkjet textile printer. The evaluation and analysis of the image files and textile patterns were based on visual assessment and measured values. The end result of this experiment was mainly to evaluate the image resolution, color difference, density and texture reproduction; specifically, outlining the advantages and disadvantages between different file formats for digital textile printing application. The investigation indicated that the JPEG, RAW, and TIFF format files appeared to have discrepancy in the original image file, and also had difference in color accuracy when reproducing on cotton fabric, but showed similar results in printable density range, print contrast, and texture reproduction. Photographing in the RAW file format and then converting to the TIFF file format ensures the image of having robust editing capability and precise print result in color accuracy. If using JPEG file format, users must caution the posterization phenomenon and discontinuous tone problem. For transparency film, either scanning in original size and then applying interpolation twice from the original size or scanning directly in target size results in similar performance. However, to achieve color accuracy, users should consider utilizing digital camera and avoid using film in the workflow. The digital textile printing provides a new and easier approach and lowers the boundary for entering the textile printing industry. This technology makes the product customization and one-of-a-kind short run become possible. However, when entering this field, the new users certainly will encounter the problems immediately related to the different image file formats. This research offers a resolution to answer the question about different file formats