Research On Still/Dynamic Image Coding And Transmission Of The National Astronomical Observatories

At present, the development of the computers and Internet technology are phenomenal, which is an impelling force for the population of other sciences such as the astronomy. We know astronomy is a science based on observation, in the past the professional astronomical researchers used to record and collect information with a telescope or other observation facilities personally, but now, many new technologies coming to the public improve methods and means for astronomy research. Both the professional and the amateur astronomical researchers hope to get the information and data they need through internet instead of standing by the telescopes and watching. Through internet they want to observe star images freely, get the star image files quickly and enjoy the real-time videos, so the National Astronomical Observatories consign us to build a streaming media transmission platform to serve the users, which can process the still images and videos to fit for the network transmission and be watched on demand by the orders.Based on the requirements mentioned above, the characters of star image files are studied and the still/dynamic image coding and transmission solution is proposed and realized in this paper. Concretely, the research achievements are as followed:Firstly, the characters of star images and files are analyzed. In order to adjust to the requirements of display of star image in internet, the star image files have been compressed with loss. The consequences show that there are still good performances for vision when the compression ratio is over 10 times; in order to adjust to the requirements of star images' storage and transmission, the star image files has been compressed lossless. An algorithm of lossless delamination compression Based on ZIP has been proposed. The conclusion is that compression ratio is increased from 1.1～1.5 to 1.8～2.3 times and better than other algorithm of lossless compressions. The requirements can be satisfied better.Secondly, a original software application using the Windows Media SDK, which can stream the still star images to a video stream file is developed, the bit rate of video flow, the size of video, the display interval of each image and other parameters can be settled manually. The application can broadcast the streams and upload the generated media streams to the video servers, and then distribute them by the servers in the internet.Lastly, a remote control system for star images streaming is designed and implemented making use of socket internet programming technologies, which can control the remote servers to execute all kinds of functions by settling different parameters in the clients.At last, the paper sums up all the work, and give the next betterment idea.