In order to utilize digital images effectively, specific techniques are needed to reduce the number of bits required for their representation. This tutorial Text provides the groundwork for understanding these image c...
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ISBN:
(数字)9780819478528
ISBN:
(纸本)9780819406484
In order to utilize digital images effectively, specific techniques are needed to reduce the number of bits required for their representation. This tutorial Text provides the groundwork for understanding these image compression tecniques and presents a number of different schemes that have proven useful. The algorithms discussed in this book are concerned mainly with the compression of still-frame, continuous-tone, monochrome and color images, but some of the techniques, such as arithmetic coding, have found widespread use in the compression of bilevel images. Both lossless (bit-preserving) and lossy techniques are considered. A detailed description of the compression algorithm proposed as the world standard (the JPEG baseline algorithm) is provided. The book contains approximately 30 pages of reconstructed and error images illustrating the effect of each compression technique on a consistent image set, thus allowing for a direct comparison of bit rates and reconstucted image quality. For each algorithm, issues such as quality vs. bit rate, implementation complexity, and susceptibility to channel errors are ***, in its many forms, is a valuable commodity in today's society, and the amount of information is increasing at a phenomenal rate. As a result, the ability to store, access, and transmit information in an efficient manner has become crucial. This is particularly true in the case of digital images. A large number of bits is typically required to represent even a single digital image, and with the rapid advances in sensor technology and digital electronics, this number grows larger with each new generation of products. Furthermore, the number of digital images created each day increases as more applications are found.
In order to utilize digital images effectively, specific techniques are needed to reduce the number of bits required for their representation. The branch of digital image processing that deals with this problem is called image c
-~- ~_vane \::y;) \ c:=::J ] 0=0 ] Dc:=JD Fig. 2. 39 Seven-segment devices for large displays and good visibility at up to 300 m can readily be obtained. Summary The number of transducer types is almost unlimited, and...
详细信息
ISBN:
(数字)9789400904132
ISBN:
(纸本)9780412342400
-~- ~_vane \::y;) \ c:=::J ] 0=0 ] Dc:=JD Fig. 2. 39 Seven-segment devices for large displays and good visibility at up to 300 m can readily be obtained. Summary The number of transducer types is almost unlimited, and in order to bring our area of study down to a more manageable size we have considered transduc ers under four main headings. Input transducers for detecting mechanical change allow us to sense force, pressure, position, proximity, displacement, velocity, acceleration, vibration and shock in all their multiple manifestations. The basis of many mechanical sensors is the strain gauge which is usually used in a bridge configuration. Other devices such as the L VDT and synchro are also widely used. Temperature transducers form another large group, and we have looked at the operating principles of the major types, with some of the techniques used in compensating for non-ideal characteristics. Radiation and chemical sensing transducers form the remaining groups. Actuators rely almost entirely on electromagnetic action and, in modern equipment, occur most commonly as solenoids and relays, including the reed relay, and stepper motors. Visual displays also come in a bewildering range of types and sizes, but, because of their ease of interfacing with electronic circuitry, the majority are based on the LED and LCD. Review questions 1. What is meant by gauge factor? 2. Define Young's modulus. 3.
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