What is the relationship between image watermarking technology and image coding technology?

Image is the main source for human beings to obtain and exchange information, so the application field of image processing must involve all aspects of human life and work. With the continuous expansion of human activities, the application field of image processing will also expand.

1) aerospace and aviation technology.

Application of aerospace technology The application of digital image processing technology in aerospace technology is not only the processing of photos of the moon and Mars by JPL, but also the application of aircraft remote sensing and satellite remote sensing technology. Many countries send many reconnaissance planes every day to take a large number of aerial photographs of areas of interest on the earth. In the past, thousands of people needed to be employed to process and analyze the photos. Now, the image processing system equipped with advanced computers is used to interpret and analyze the photos, which not only saves manpower, but also accelerates the speed, and can also extract a lot of useful information from the photos that cannot be found manually. Since the late 1960s, the United States and some international organizations have launched resource remote sensing satellites (such as LANDSAT series) and sky laboratories (such as SKYLAB). Because the imaging conditions are affected by the position, attitude and environmental conditions of the aircraft, the image quality is always not very high. Therefore, it is not economical to obtain images through simple and intuitive interpretation at such an expensive price, and digital image processing technology must be adopted. For example, LANDSAT series Landsat satellites use a multi-band scanner (MSS) to scan and image every region of the earth at a height of 900km with a period of 18 days, and its image resolution is roughly equivalent to more than ten meters on the ground or 100 meters (for example, LANDSAT-4 is launched at 1983 with a resolution of 30m). These images are processed (digitized and encoded) in the air and stored on magnetic tape. When the satellite passes over the ground station, it is transmitted at high speed, and then analyzed and interpreted by the processing center. Many digital image processing methods must be used in the imaging, storage, transmission and interpretation of these images. At present, all countries in the world are using the images obtained by land satellites to carry out resource surveys (such as forest surveys, marine sediments and fisheries surveys, water resources surveys, etc.). ), disaster detection (such as pest detection, fire and water detection, environmental pollution detection, etc. ), resource exploration (such as oil exploration, mineral exploration, geographical location exploration and large-scale project analysis, etc. ), agricultural planning (such as soil nutrition, water content, crop growth, yield estimation, etc.). ), and urban planning (such as. China has also carried out some practical applications in the above aspects and achieved good results. Digital image processing technology has also played a considerable role in weather forecasting and the study of other planets in space.