Systematic Survey on Digital Still Cameras 2 Motokazu Ohkawa Abstract Imaging is a culture that only humans can freely make use of as a means of communicating information, and from ancient times – even prior to the birth of civilization – we have exchanged, communicated, and recorded information by means of images. The camera was invented and has evolved as a tool for recording images easily and accurately. Although the origin of the camera goes back to the camera obscura, which was used to draw a picture by tracing an image focused on a screen in a dark box through a pinhole or a lens, since the advent of the Daguerreotype, the first real camera, which was announced in 1839, until the early 2000s, cameras have developed as tools for recording images using a photochemical reaction technique. It was during 1981 that an electronic camera was announced that converted captured images to electronic signals by means of an image sensor and recorded them to a dedicated floppy disk. Known as the “Floppy Camera,” this was the first camera to record images using a method other than the photochemical reaction technology employed with conventional silver halide cameras. However, the still images grabbed from the analog video signal by the Floppy Camera, which appropriated the technologies employed in existing video cameras to view images on a TV screen, was unable to produce images of sufficient quality to replace conventional cameras. At almost the same time, Toshiba announced a prototype that recorded images digitally, and unlike the traditional analog technology used in electronic cameras, which suffered from dropout in the recording and reproduction stages, the digital signal processing techniques employed actually improved image quality. However, as image playback was slow due to the recording media (audio cassette tape) and poor image compression technology employed, and the fact that images were displayed on a TV screen, it was of no real practical use. In the late 1980s, flash memory, a type of large-capacity non-volatile semiconductor storage, was developed and a digital still camera (DSC) that electronically recorded digital image signals on such media was announced. However, this too was unable to replace silver halide cameras due to poor image compression efficiency, the extremely high cost (1 million+ JPY), and image quality that was still just enough for viewing on a TV screen and not high enough for printing purposes. JPEG, a high-efficiency/high-performance image compression technology, was established as an international standard in 1992, the same year that Japan proposed its use as a standard for consumer DSCs. At the same time, the price of memory dropped and Casio's launch of the QV-10 at a price of 65,000 JPY in 1995, followed by the QV-10A at 49,800 JPY in 1996, triggered the expansion of the consumer DSC market. During the mid-1990s, with the rapid popularization of the personal computer and the advent of the internet, exchanging images electronically became more common, and the development of digital electronic appliances, such as DTVs and DVDs, brought on the Digital Information Age. The DSC is not simply a device that records images electronically rather than using the photochemical method employed with conventional silver halide cameras, but has established itself as an image-capturing peripheral in a digital environment that is capable of interacting with computers, the internet and printers. Furthermore, as DSCs are designed to work with PCs rather than being confined to working with TVs, restrictions in terms of image size have been removed, and image quality has remarkably improved to the extent that DSCs have quickly come to replace silver halide cameras, with total annual sales and production exceeding those of silver halide cameras in 2000 and 2002 respectively. Today, DSCs boast annual sales in excess of 1 trillion JPY and the technologies and formats developed for DSCs have already been transferred into mobile phones, opening up yet another new market: image communication devices. It should be noted that the DSC, which was born in Japan and has gone on to conquer world markets, was made a reality by the various technologies developed by Japanese industries. Furthermore, as Japanese electronics manufacturers pioneered this field, they have made it possible for Japan to maintain leadership in this market, and with the standardization of DSC specifications, consumers will no longer put off buying products for reasons of future incompatibility, and DSC manufacturers are free to concentrate on improving their technology within an established framework. Profile Contents Motokazu Ohkawa Chief Researcher, Center of the History of Japanese 1 Introduction .................................................... 3 Industrial Technology, National Museum of Nature 2 The History of Image Culture ........................ 5 and Science 3 Digital and Fourier Transform ....................... 8 4 The History of the Camera ........................... 13 1962 Graduated from the Physics Department of 5 DSC Structure .............................................. 25 Tohoku University's Faculty of Science and 6 DSC Characteristics ..................................... 31 the same year joined Tokyo Shibaura Electric 7 DSC-Related Technology and Co., Ltd. (now known as Toshiba Systematization ............................................ 36 Corporation), where he was engaged in the 8 Image Compression and Formats ................. 53 research of acoustics at the company's Central 9 Standardization of DSCs .............................. 65 Research Laboratory. After that he was 10 The Future of DSCs ..................................... 68 engaged in the development of CATV, etc., at 11 Discussion and Acknowledgements ............. 74 the Consumer Electronics Research Center. DSC Genealogy .................................................. 77 1988 Engaged in digital camera development. Appendix 1. List of significant models. ............. 78 1991 Digital Camera Technology Committee Appendix 2. Chronology .................................... 79 Chairman of JEITA (Japan Electronics and Information Technology Industries Association) (originally JEIDA: Japan Electronic Industries Development Association). ISO TC42 expert. 1995 Relocated to the High-tech Visual Promotion Center. 2000 Camera & Imaging Products Association (CIPA) technical adviser. 2007 Resigned from CIPA. Chief Survey Officer, Center of the History of Japanese Industrial Technology, National Museum of Nature and Science until stepping down at the end of March 2008. Chairman of the Japan Color Standardization Committee (JSA) during that time. 2 National Museum of Nature and Science Technology Systematization Survey Report Vol.10 2008.March 1 Introduction Only humans use images as a means of electronic devices rapidly expanded and communicating information, and consumer-level digital appliances, such as communicating information by means of DSCs, flourished. Moreover, DSCs fused images is something that is unique to human with mobile phones to create new culture. Thirty thousand or more years ago, communication tools, resulting in the our ancestors created an image culture to dramatic advancements in image-based convey information through images and to communications. leave a record of their feelings. Over the In addition to the abovementioned centuries, humans have devised and development of the digital information developed ways of more easily and accurately environment, the background to the rapid creating and saving images. development of DSCs included technological As a result of such efforts, while on one innovations such as memory and image hand this led to the birth of the “pictorial art sensor-related semiconductor technology and culture,” which sought to be more artistic, on image processing technology, such as the the other hand it led to the advent of the JPEG format. However, special mention “camera culture,” which sought a greater needs to be made of the fact that DSC degree of accuracy. development originated in Japan, that the The history of cameras is said to have standardization of international standards was begun approximately 170 years ago with the carried out at the initiative of Japan, and that announcement of the Daguerreotype in 1839. Japan basically held a monopoly on the Since then, over the course of more than 150 market. There are very few such examples in years, using the silver halide photochemical the consumer equipment market. reaction, cameras have been the means by Furthermore, the camera market, which had which images of subjects have been recorded; been monopolized by the traditional camera in other words, they have gone through manufacturers as the conventional precision various technological revolutions as the silver machinery industry, became the launching halide film camera. During the early 1980s, pad for electronic equipment manufacturers, however, electronic cameras appeared that who were experts in electronics and software electronically recorded images, and by the development, to launch out into the DSC end of the 1980s, digital still cameras (DSCs) market in quick succession. On account of had been announced that recorded images as this, the camera market, where up until that digital signals in semiconductor memory. time product cycles had been long, with Characteristics of early DSCs included the flagship models being used in some cases for fact that they were instant, that there was no decades, saw a shortening of product