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—In this paper, an image accreditation technique by embedding digital watermarks in images is proposed. The proposed method for the digital watermarking is based on the wavelet transform. This is unlike most previous work, which used a random number of a sequence of bits as a watermark and where the watermark can only be detected by comparing an(More)
A lossless wavelet-based image compression method with adaptive prediction is proposed. Firstly, we analyze the correlations between wavelet coefficients to identify a proper wavelet basis function, then predictor variables are statistically test to determine which wavelet coefficients should be included in the prediction model. At last, prediction(More)
A gradient image describes the differences of neighboring pixels in the image. Extracting edges only depending on a gradient image will results in noised and broken edges. Here, we propose a two-stage edge extraction approach with contextual-filter edge detector and multiscale edge tracker to solve the problems. The edge detector detects most edges and the(More)
We present a lensfree digital microscopy platform implemented on a cell-phone. It operates based on digital in-line holography and provides a compact and lightweight alternative to conventional microscopes, such that the cell-phone is modified with an inexpensive attachment weighing only ~38 grams. This lensfree cell-phone microscope captures holo-graphic(More)