Research Of Single-pixel Digital Camera

In 2006, Duarte M F, Davenport M A, Takhar D and others applied compressed sensing theory to optical imaging, and successfully designed a typical single-pixel digital camera. Single-pixel digital camera strictly meet the compressed sensing theory, which verified its correctness, and broke the only high pixel development pattern of the modern cameras, achieved the aim that the image could be reconstructed by using a single photon detector and the data which were far less than the original image information, made the development of the digital camera be no longer limited to the size of the electronic sensors, opened up a new development direction of digital cameras. Single-pixel digital camera becomes one of the development tend of digital cameras because of its many unique advantages. In order to further research single-pixel digital cameras, in this thesis, the following aspects are performed.(1) The basic theory of single-pixel digital camera, compressed sensing theory, is systematically introduced, which includes three contents: sparse representation of signal, measure matrix and reconstruction algorithm.(2) Aimed at overcoming the deficiency of the reconstruction algorithm of compressed sensing theory, three aspects of improvements are proposed. 1) When a greedy algorithm is applied to recovery images, whether a line by line or a column by column reconstruction should be chosen depends on the image characteristics. 2) Improved MP and OMP algorithms with adaptive iterations are proposed. 3) An improved greedy algorithm combined distance with inner product is proposed. A comparison of the recovered images reconstructed from the three kinds of improved reconstruction algorithms and those from the original algorithms through Matlab simulation indicate that the improved algorithms are conducive to further improve the image quality.(3) The theory of single-pixel digital camera is given in detail and depth, includes: 1) The classical structure and experimental principle of single-pixel digital camera; 2) The core component of the single-pixel digital camera-digital micro mirror device; 3) A new approach is proposed, which makes full use of all pixels of the DMD by adding the light collection in the direction of minus 12 degrees without changing the number of measurements; 4) The measurement matrixes which can be loaded are introduced, including: partial Hadamard matrix, binary permuted block diagonal matrix, sparse binary random matrix, toeplitz and loop measurement matrix; At the same time, scrambled block Hadamard with great development potential and likely to be loaded in the hardware equipment is introduced; 5) The rearranged method of measurement matrix and target image in reconstruction algorithm are recommended, and the simulation results of the experiment of single-pixel digital camera are showed; 6) A series of advantages of the single-pixel digital camera are listed, which effectively illustrate the significance of the research of single-pixel digital camera; 7) The requirements in the single pixel digital camera are listed.(4) Experiments on single pixel digital camera are carried out. Experimental instruments and the experimental platform for single-pixel digital camera are introduced. In the thesis, a two-step idea for adjusting experimental light path and an operation method for eliminating the background light are presented and high quality images are successfully reconstructed with the two-step method. All of the above provide a useful reference for the further research and development of the single-pixel digital camera.(5) Further development and practical application prospects of single-pixel digital camera are put forward.