摘要:
A method of generating a binary Sel plane for image compression is disclosed. The method first generates a 2 bit gray selector (GraySel). This 2 bit selector is then processed in a second stage to produce a binary Sel decision which minimizes the compression noise evident in the reconstructed image. The method used here to generate the 2 bit GraySel applies a set of prioritized rules over a small 3null3 window that is well suited for segmenting synthetic, PDL generated images that are typically free of scanner noise. The method not only marks the proper sense of the selector when it is known, but also include a 3rd state that indicates that the selector decision is weak or unknown. This weak decision can then be optimized in the second stage process based on strong edges information in the neighborhood.
摘要:
A method and a system for dynamically thresholding an image signal. The system comprises a computing block. The computing block receives the image signal and a minimum and a maximum within each of a set of windows centered on the current pixel in the image signal, and computes, for each of the windows, based on the current pixel and the respective minimum and maximum, a respective indicator representing the distance and direction of the current pixel relative to a respective threshold plane, and outputs a control signal based on the indicators.
摘要:
A method and a system for dynamically thresholding an image signal. The system comprises a computing block. The computing block receives the image signal and a minimum and a maximum within each of a set of windows centered on the current pixel in the image signal, and computes, for each of the windows, based on the current pixel and the respective minimum and maximum, a respective indicator representing the distance and direction of the current pixel relative to a respective threshold plane, and outputs a control signal based on the indicators.
摘要:
Methods and systems include a dependent min-max module the receives image data and generates a dependent Min value and a dependent Max value within a window around a pixel of interest. A dynamic threshold module, based on the dependent Min and Max values, generates continuity data and enhanced data suitable for identifying, for example, blobs.
摘要:
A method and a system for separating an image signal into a set of image planes. The system comprises a min-max module, a dynamic threshold module and a separation module. The min-max module receives the image signal, searches for a minimum and maximum within at least one window centered on a current pixel in the image signal. The dynamic threshold module computes, for the window, based on the respective minimum and maximum received from the min-max module and the current pixel, a respective indicator representing the distance and direction of the current pixel relative to a respective threshold plane, and outputs a control signal based on the indicator. The separation module separates the image signal into the set of image planes in accordance with the control signal by including a representation of the current pixel in at least one of the image planes.
摘要:
A method and a system for de-screening an image signal. The system comprises a filter bank, a control module and a blend module. The filter bank filters the image signal and produces a set of filter output signals. The control module generates at least one control signal based on the image signal and some of the filter output signals. The blend module dynamically blends the filter output signals in accordance with the control signal to produce a de-screened output signal.
摘要:
A method and a system for computing the function value of an input node based on function values of known nodes. A database of known nodes and their corresponding function values is formed. The known nodes are located such that a distance between any two adjacent known nodes is an integer power-of-two number. The database is searched for a first node such that the input node is located between the first node and an adjacent second node. The difference null between the input node and the first node is computed. Then null is shifted to the right by k positions, k being the logarithm in base 2 of the distance between the first and second nodes. The input node function value is computed by combining the first node function value with the product of the shifted null and the difference between the function values of the second and first nodes. When used in MRC context, the above method and system is applied to each of the color MRC planes individually, instead of the merged output. The resulting performance is approved since most if not all of the color MRC planes are sub-sampled.
摘要:
A Gamut Enhance Module (GME) is disclosed for applying 3 independent Tone Reproduction Curves (TRC) to each of the color components of an input image. The implementation is done via three independent and fully programmable 1D lookup tables. The input to the Gamut Enhance Module is the output DSS from a Scaling Module (SCL), representing a scaled and de-screened version of the source image. The output is a gamut-mapped signal GME. The GME unit includes special logic to neutralize (set to gray) or preserve input colors.
摘要:
A method and a system for controlling de-screening of documents. The control system is included in a de-screening system including a bank of filters. The filter bank receives an image signal and produces a set of filter output signals. The control system comprises a contrast module, a halftone estimate module and a pixel control module. The contrast module receives a filter output signal from a filter having a large filter span and produces a contrast signal. The halftone estimate module receives the image signal and a filter output signal from a filter having a small filter span and produces an estimated frequency signal and a halftone weight signal. Based on the contrast signal, the estimated frequency signal and the halftone weight signal, the pixel control module produces a control signal which includes information regarding which of the filter output signals are to be blended and the proportion of blending.
摘要:
A method and a system for separating an image signal into a set of image planes are disclosed. The system comprises a way to perform resolution conversion from low resolution to high resolution binary images either for synthetic or scanned imagery by using template matching with pattern replacement. More specifically, the invention applies resolution conversion to the selector plane of mixed raster content images. For selector planes in which edges are encoded (vs. region classification), template matching/pattern replacement works well, and does not affect halftoned regions, as they are not encoded in this image.