摘要:
The present invention discloses a digital halftoning method. The method comprises steps of: (a1) dividing an original image into non-overlapping blocks; (a2) obtaining a Least-Mean-Square trained (LMS-trained) filter by comparing at least a training image and a halftone result corresponding to the training image (a3) optimizing a class matrix with the LMS-trained filter, which involves the diffused area and the diffused weightings; and (a4) processing the non-overlapping blocks by performing a dot diffusion procedure with the optimized class matrix and the diffused weightings to generate a halftone image corresponding to the original image. A detailed class matrix optimizing method as in the above-mentioned step (a3) is also disclosed.
摘要:
An object detection method and an apparatus thereof are provided. In the object detection method, a plurality of images in an image sequence is sequentially received. When a current image is received, a latest background image is established by referring to the current image and the M images previous to the current image, so as to update one of N background images, wherein M and N are positive integers. Next, color models of the current image and the background images are analyzed to determine whether a pixel in the current image belongs to a foreground object. Accordingly, the accuracy in object detection is increased by instantly updating the background images.
摘要:
A mutual optimization method for class matrix and diffusion weighting used in a halftone image processing technique and a mutual optimization system thereof are provided. In the method, a mutual optimization of a plurality of diffusion weightings and a class matrix used in a dot diffusion process is performed based on a concept of simulated annealing in order to avoid converging to local solution, so as to ensure an image quality of a halftone image generated by the dot diffusion process. Besides, since the mutual optimization method is for a hexagonal class matrix, a block effect appearing in the halftone image can be significantly reduced.
摘要:
A digital halftoning method and a method for constructing a class tiling map are disclosed. The present invention utilizes to arrange class matrixes in a staggering form such that adjacent class matrixes exist a staggering shift. Also, the class tiling map is constructed in this way. Then, a dot diffusion procedure is performed to an original image with the class tiling map so as to generate a halftone image corresponding to the original image. The present invention is capable of solving the problem of a periodic appearance caused by traditional dot diffusion.
摘要:
A digital halftoning method and a method for constructing a class tiling map are disclosed. The present invention utilizes to arrange class matrixes in a staggering form such that adjacent class matrixes exist a staggering shift. Also, the class tiling map is constructed in this way. Then, a dot diffusion procedure is performed to an original image with the class tiling map so as to generate a halftone image corresponding to the original image. The present invention is capable of solving the problem of a periodic appearance caused by traditional dot diffusion.
摘要:
An image data processing system includes an image input module, a bit map generation module and an encoding module. The image input module receives an image and secret information and obtains at least one gray-level image according to image. The bit map generation module generates a bit map image according to gray-level image and generates an ordered dithering block truncation coding (ODBTC) image according to bit map image and gray-level image. The encoding module generates an encoded gray-level image according to bit map image and secret information, wherein the encoding module divides gray-level image into image blocks, finds candidate blocks with close black and white pixel numbers among the image blocks, selects high frequency blocks belong to the high frequency region of the image from candidate blocks, and randomly embeds secret information into high frequency blocks to generate encoded gray-level image with secret information embedded therein.
摘要:
A method is performed to hide a watermark in two halftone images or in a single halftone image. The halftone image contains information of the hidden watermark, and each pixel value of the halftone image is associated with a corresponding offset value. The offset value is determined according to a corresponding pixel value of the watermark and a corresponding pixel value of another halftone image. The offset value is used to compensate a corresponding input value and a corresponding original error value of the halftone image.
摘要:
An image processing method combining compression and watermark techniques is provided. In the method, a block is taken as a unit, and two ordered dither arrays mutually conjugate are used to code an original image, so as to insert information of a watermark into the original image during the coding process. Accordingly, the method generates a compressed image gives consideration to the compression ratio, the image quality and the data safety. On the other hand, the method also provides a procedure to extract the watermark from the compressed image, in order to verify whether the compressed image has been modified illegally.
摘要:
A system for hiding secret data in halftone images is disclosed. The system includes an image input module, a halftoning processing module and an image output module. The image input module reads an original image data and a secret image data. The halftoning processing module is coupled to the image input module and receives the original image data and the secret image data, performs a first error diffusion process to the original image to generate a first halftone image and performs a second error diffusion process to the original image data and the secret image data to generate a second halftone image. The image output image module is coupled to the halftoning processing module and outputs the first halftone image and the second halftone image, wherein the second error diffusion process comprises adding or subtracting a variable noise strength to or from each pixel of the secret image.
摘要:
A blind wavelet-based watermarking method is provided to extract one or more embedded watermarks form one or more high subbands of a watermarked image generated by 1-level or 2 level wavelet transform. One or more least-mean-square (LMS) filters are trained to predict the data sets in the high subbands of an original image by converting a low subband of the watermarked image. Therefore, the one or more embedded watermarks could be extracted by comparing the predicted data sets in the high subbands with data sets in corresponding subbands of the watermarked image.