Digital Image Processing Demonstration System

Image is the general term for a variety of graphics and video, which is a similar, vivid description or photo for objective objects, it constitutes a vivid thinking pattern to help us to learn, to think. The 21st century is an era full of information, as the foundation of human’s visual perception of the world, image is an important means for human to access, express and convey information. Digital Image Processing is known as an image processing, which uses computers for image processing, analysis, in order to achieve the desired technical result. Digital image processing refers to a large two-dimensional array captured by industrial cameras, camcorders, scanners and other equipment. The elements of the array are called pixels, whose values are the gray values. Digital image processing techniques typically include image compression, enhancement and restoration, matching, recognition and description and ect. With the continuous development of science and technology, digital image processing has become a hot topic of research, and has been widely used in daily life.Learning digital image generally starts from the image analysis. There are many common methods of image analysis:firstly, understand the format of an image (such as BMP, JPG, etc.), type (such as a binary image, color image), size (width and height of the image), and other basic information, to has a basic understanding of the image. And then, begin to contact to the internal information of the image, generally with the method of gray histogram, intuitive image histogram expresses all of the data of the inside of the image. After analysis of the image, the image can be processed according to individual needs. Normally, the commonly used image processing techniques for image are edge detection, image compression and image watermarking, image encryption and image segmentation, etc. When the processing target is determined, we can select the algorithm used in the process of the image processing, which may be the classical algorithm or be improved by ourselves. After getting the processed result, we need to analyze the result image and compare it with the original image data, to see whether it has achieved the desired goal or not. In the process of the image processing, the image may encounter some noise attacks, such as Gaussian white noise, salt and pepper noise, etc. Especially after encrypted, the image often meets some compression attacks, geometric attacks, etc. To drop the impact of various types of attacks to a relatively small extent, has become an important direction of digital image processing.Firstly, this paper presents a digital image encryption and decryption algorithm, based on the Arnold scrambling algorithm and 3DES encryption algorithm, the algorithm makes some improvements and it retains the advantages of the original algorithms, and increases the key space.Then, the paper develops the Digital Image Processing Demonstration System. The system is mainly used in the field of teaching, it plays a supporting role in the digital image processing course, combining theory with practice, improving boring teaching and learning environment, activing the atmosphere, and enhancing students’ interest. Using Microsoft Visual Studio 2010 as the development platform and C# as the development language, the system’s application can be used directly in the Windows system, and the range is broad. Generally speaking, the main function of the system can be divided into three parts:image analysis functions, image attack functions, image processing functions. Image analysis functions include:gray histogram, linear point operations and so on; Image attack functions are given priority to with added noise, including Gaussian white noise and salt and pepper noise; The range of image processing functions is larger:histogram stretching and equalization, LSB chaos and image watermark, Patchwork watermark, Haar wavelet watermark,3DES encryption. The design of the whole system has a special focus on the basic and the representative, and all of the algorithms selected in the system are classic algorithms in various areas to help study the theory of digital image processing.