A watermarking algorithm of color images based on the quaternion Fourier Transform (QFFT) and improved
quantization index algorithm (QIM) is proposed in this paper. The original image is transformed by QFFT, the
watermark image is processed by compression and quantization coding, and then the processed watermark image is
embedded into the components of the transformed original image. It achieves embedding and blind extraction of the
watermark image. The experimental results show that the watermarking algorithm based on the improved QIM algorithm
with distortion compensation achieves a good tradeoff between invisibility and robustness, and better robustness for the
attacks of Gaussian noises, salt and pepper noises, JPEG compression, cropping, filtering and image enhancement than
the traditional QIM algorithm.
The key problem of ultra-wide band (UWB) imaging system is the low signal to noise ratio (SNR). A novel multichannel
blind image restoration algorithm based on sub-space and constrained least square (CLS) is presented and
applied into UWB system to deal with this issue. Based on the improved model of the UWB echo, the high resolution of
UWB image can be equivalent to multi-channel blind image restoration. A new cost function is proposed by considering
the concept of sub-space as the limitation of blur identification. And the proposed algorithm converts the image
estimation to alternating-minimizing the cost functions. Experimental results prove that the proposed algorithm is
effective at improving the resolution of UWB image even at low SNR.
A novel method for Computerized tomography (CT) cerebral hemorrhage (CH) image automatic segmentation is presented in the paper, which uses expert system that models human knowledge about the CH automatic segmentation problem. The algorithm adopts a series of special steps and extracts some easy ignored CH features which can be found by statistic results of mass real CH images, such as region area, region CT number, region smoothness and some statistic CH region relationship. And a seven steps' extracting mechanism will ensure these CH features can be got correctly and efficiently. By using these CH features, a decision tree which models the human knowledge about the CH automatic segmentation problem has been built and it will ensure the rationality and accuracy of the algorithm. Finally some experiments has been taken to verify the correctness and reasonable of the automatic segmentation, and the good correct ratio and fast speed make it possible to be widely applied into practice.
In this paper, a real-time demosaicing generic model is presented, which is concise, easy to implement, resources-saving
and robust. With the model, multiple displaying demosaicing subsystems can be realized in terms of a Bayer
pattern color filter array. A LCD displaying subsystem is designed by FPGA, and the waveform simulated is presented.
The monitoring results of a real scene are captured and illustrated. To prove the LCD monitoring results, the application
background of the LCD subsystem is given, which is a multiple channel CMOS image sampling system. The three
images exposed synchronously in the background system and the pictures stored are shown, one of which is identical to
the scene monitored by the LCD subsystem. Finally, to demonstrate the generality of the model, the test results of a CRT
demosaicing displaying subsystem designed with the model in the background system are given.
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