The hottest image processing based on Blackfin and

2022-10-23
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Image processing based on Blackfin and its performance compared with ISP in CMOS sensor

image is the main source for human to obtain and exchange information. Therefore, the application field of image processing must involve all aspects of human life and work. With the continuous expansion of the scope of human activities, the application field of image processing will also continue to expand. It covers aerospace, medical equipment, communication engineering, military security, culture and art and many other aspects. In recent years, with the advent of consumer products, especially photography, digital cameras, digital video cameras and a series of digital products, the image signal processing function contained in these video devices has gradually been recognized and concerned by people. With the rapid development of security products such as digital TV, IP camera, web camera and surveillance camera in recent years, it shows that the market demand for intelligent monitoring is growing, which is also a process of continuous enrichment and improvement of image signal processing technology. In these image signal processing, including auto focus, auto exposure, auto white balance, color transformation, backlight compensation and so on, are some basic image processing algorithms

traditional image signal processing is completed by a special image processor. With the continuous development of CMOS technology, there are also single-chip products that integrate image signal processing (ISP) into CMOS image sensors. With the help of its internal integrated functional modules, such sensor products can complete some image signal processing algorithms, including automatic exposure, automatic white balance, color transformation and other basic algorithms. The emergence of such ASIC products was once controversial, because although the ISP built into the sensor has the advantages of reducing power consumption and saving occupied area, in terms of application alone, the cost of integrating the ISP into the sensor is much higher than that of integrating the ISP into the mobile multimedia processor or baseband. With the improvement of sensor resolution, more and more sensors will only integrate the necessary circuits to output digital signals, and integrate the functions of image processing and compression into mobile multimedia processors or baseband. In terms of imaging quality, it is better to integrate powerful image processing functions in mobile multimedia processors, and this trend will become more obvious with the improvement of resolution. Therefore, the industry has always predicted that ISP and CMOS sensors will deviate from the trend of integration. However, judging from the new product lines launched by CMOS sensor suppliers in recent years, this prediction has not been fulfilled. Because we see that front-line CMOS sensor suppliers such as aptina and omnivision have launched the latest CMOS image sensor single-chip products with built-in ISP, and are constantly improving their functions and expanding their application fields. At present, these single-chip products not only have a variety of image processing functions, including exposure control, gamma correction, white balance, color saturation adjustment and gray level control, but also provide excellent low illumination performance. In the night vision environment, they also have excellent near-infrared response performance, which can provide camera manufacturers with more perfect automatic white balance and automatic exposure functions, and the image performance is not inferior. A series of excellent performance makes it gradually develop from the initial application of photography, digital cameras and digital cameras to the field of new security products such as web cameras and surveillance cameras. Its expansion trend is still continuing, and there is a great potential for a prairie fire

it should be said that in the application of consumer products such as digital cameras that pursue small and light weight, the CMOS sensor with built-in ISP has certain competitive advantages. Its low power consumption and small area performance as well as the continuously reduced cost with the production scale make it the darling of many application manufacturers. At the same time, we should see that this CMOS sensor scheme with built-in ISP can only complete some less complex algorithms at present. With the continuous improvement of intelligent requirements, consumer products, especially video surveillance and other security products, require higher video processing functions, which also requires more complex algorithms, and complex algorithms put forward higher requirements for the processing capacity of the main chip. For example, traditionally, many surveillance cameras are based on NTSC (352) pixel resolution × Formulate policies to support the implementation and utilization of new materials industry 240) or pal (352 × 288), and the less complex M-JPEG format is mainly used in the compression format, so the processing performance of DSP is not high. However, with the rapid development of video surveillance market, people expect higher image definition and higher frame rate. In terms of resolution, the industry expects D1 (704 × 576) or higher resolution; In terms of encoding and decoding, it is expected to adopt the complex MPEG-4 compression format. At the same time, with the development of network interconnection, when DVR, DVS or IP cameras are used as network terminals, it is also necessary to consider how to occupy less bandwidth in the transmission process. Therefore, MPEG-4 is evolving to the coding formats of H.264 and AVS with higher compression ratio. These more advanced video signal resolutions and compression formats will greatly increase the demand for processing power in the core processor. In addition to powerful processing power, the processor platform is also required to provide sufficient flexibility. At present, although H.264 is the most popular compression format in the industry, it is expected to become the mainstream in the next few years. However, due to the advantages of encoding and decoding algorithms such as M-JPEG, H.263, MPEG4 and H.264, and the diversification of market demand, these standards will coexist for a period of time. To be competitive, support must be given to as many standards as possible. At the same time, media processing formats and algorithms are also constantly updated. When more advanced algorithms appear, engineers hope to simply upgrade the software based on the original solution, rather than redesign. At the same time, video surveillance has its special requirements for security technologies such as confidentiality. Whether it is commercial or home applications, the device itself is threatened by illegal intrusion and hacker attacks. It is undoubtedly a great challenge to product design to fully ensure the security of the device. At this time, the single-chip CMOS sensor product with built-in ISP shows its inherent shortcomings. Because it cannot complete such complex functions, it needs to be equipped with a separate image processor to meet the requirements. Although ASIC has cost advantages, it has inherent disadvantages in dealing with the improvement and upgrading of media formats and algorithms. In the video surveillance market with the continuous evolution of audio and video standards and the continuous improvement of algorithms, ASIC is much inferior

here, traditional processor suppliers such as ADI, Ti, NXP, etc. have irreplaceable competitiveness. Among them, the new embedded processor Blackfin series designed by Adi company to meet the computing requirements and power consumption constraints of today's embedded audio and video and communication applications is particularly eye-catching for its outstanding performance

image is the main source for human to obtain and exchange information (that is, the sample is closed, in the closed, intersection or out of gauge). Therefore, the application field of image processing must involve all aspects of human life and work. With the continuous expansion of the scope of human activities, the application field of image processing will also continue to expand. It covers aerospace, medical equipment, communication engineering, military security, culture and art and many other aspects. In recent years, with the advent of consumer products, especially photography, digital cameras, digital video cameras and a series of digital products, the image signal processing function contained in these video devices has gradually been recognized and concerned by people. With the rapid development of security products such as digital TV, IP camera, web camera and surveillance camera in recent years, it shows that the market demand for intelligent monitoring is growing, which is also a process of continuous enrichment and improvement of image signal processing technology. In these image signal processing, including auto focus, auto exposure, auto white balance, color transformation, backlight compensation and so on, are some basic image processing algorithms

traditional image signal processing is completed by a special image processor. With the continuous development of CMOS technology, there are also single-chip products that integrate image signal processing (ISP) into CMOS image sensors. With the help of its internal integrated functional modules, such sensor products can complete some image signal processing algorithms, including automatic exposure, automatic white balance, color transformation and other basic algorithms. The emergence of such ASIC products was once controversial, because although the ISP built into the sensor has the advantages of reducing power consumption and saving occupied area, in terms of application alone, the cost of integrating the ISP into the sensor is much higher than that of integrating the ISP into the mobile multimedia processor or baseband. With the improvement of sensor resolution, more and more sensors will only integrate the necessary circuits to output digital signals, and integrate the functions of image processing and compression into mobile multimedia processors or baseband. In terms of imaging quality, it is better to integrate powerful image processing functions in mobile multimedia processors, and this trend will become more obvious with the improvement of resolution. Therefore, the industry has always predicted that ISP and CMOS sensors will deviate from the trend of integration. However, judging from the new product lines launched by CMOS sensor suppliers in recent years, this prediction has not been fulfilled. Because we see that front-line CMOS sensor suppliers such as aptina and omnivision have launched the latest CMOS image sensor single-chip products with built-in ISP, and are constantly improving their functions and expanding their application fields. At present, these single-chip products not only have a variety of image processing functions, including exposure control, gamma correction, white balance, color saturation adjustment and gray level control, but also provide excellent low illumination performance. In the night vision environment, they also have excellent near-infrared response performance, which can provide camera manufacturers with more perfect automatic white balance and automatic exposure functions, and the image performance is not inferior. A series of excellent performance makes it gradually develop from the initial application of photography, digital cameras and digital cameras to the field of new security products such as web cameras and surveillance cameras. Its expansion trend is still continuing, and there is a great potential for a prairie fire

it should be said that consumer products such as digital cameras that pursue small and light weight are increasingly used in the product applications in the field of Stomatology. CMOS sensors with built-in ISPs have certain competitive advantages. Their low power consumption and small area performance, as well as the continuous reduction of costs with the production scale, make them the darling of many application manufacturers. At the same time, we should see that this CMOS sensor scheme with built-in ISP can only complete some less complex algorithms at present. With the continuous improvement of intelligent requirements, consumer products, especially video surveillance and other security products, require higher video processing functions, which also requires more complex algorithms, and complex algorithms put forward higher requirements for the processing capacity of the main chip. For example, traditionally, many surveillance cameras are based on NTSC (352) pixel resolution × 240) or pal (352 × 288), and the less complex M-JPEG format is mainly used in the compression format, so the processing performance of DSP is not high. However, with the rapid development of video surveillance market, people expect higher image definition and higher frame rate. In terms of resolution, the industry expects D1 (704 × 576) or higher resolution; In terms of encoding and decoding, it is expected to adopt the complex MPEG-4 compression format. At the same time, with the collateral

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