摘要:
A pure rendering intent is used to render text and line art in color imaging systems. A CMY image goes through a one hundred percent under color removal process creating a CMYK image. The CMYK image is processed by a set of clamping tone reproduction curves. The clamping tone reproduction curves shift nearly saturated colors to total saturation. The result is a rendering of text and line art that has improved clarity and legibility.
摘要:
A method for determining and assigning colorimetry and authorship device information to an image of unknown colorimetry includes iteratively displaying the image on a display device and selecting possible source device profiles for transforming the image. When a possible source device is indicated or selected, the source device is emulated on the display device and the image is displayed through the emulation. A user can then evaluate the indicated source device and if necessary indicate a new possible source device. When the most likely source device is selected, further image processing is enabled. The method can be carried out on a color image processor comprising a source device emulator and display device interface. The display device interface can use a display device profile for profile connection space to display device transformation.
摘要:
A document processing system and a method for classifying an input image or region thereof as either a synthetic graphic or a natural picture, is disclosed. The system includes an image input subsystem, a processing subsystem for processing image data provided by the image input subsystem, and software/firmware means operative on the processing subsystem for a) low-pass filtering image data representative of the input image or region thereof to produce low-pass filtered pixel values; b) determining a smoothness value for each of a plurality of low-pass filtered pixel values; c) generating histogram data from the smoothness values; d) determining a texture metric for the input image or region thereof from a subset of the histogram data; and e) thresholding the texture metric to classify the input image as either a synthetic graphic or a natural picture.
摘要:
A method and color image processor for rendering a color image includes selective blending between transforms or rendering intents. Based on a pixels location within a color gamut of a first device the pixel is mapped to a color gamut of a second device as directed by a first transform or rendering intent, a second transform or rendering intent or a blend between the first and second transforms.
摘要:
A transformation function defines a relationship between a first color space and a second color space. The transformation function is edited by producing first and second outputs of an image in the first and second color spaces, respectively. The outputs are related in accordance with the transformation function. A portion of the first output, which corresponds to a portion of the second output including a color to be modified, is selected via a graphical user interface. A desired amount to modify the color is specified. A correction function is determined in accordance with the desired amount. The transformation table is edited in accordance with the monotonic correction function.
摘要:
In a hi-fi color printing system, an inverted halftone screen is provided having the same angle and frequency as a halftone screen for an opposing color. The dots of the inverse halftone screen are configured to be located midway between the centers of the dots of the half-tone screen. The halftone screen and inverted halftone screen are used in the printing process to extend the gamut of colors within a printing system, render improved neutral colors, and provide an improved transition through neutral regions of color space. The present invention allows for additional printing of multiple colors without the need for increasing the number of screens used in the image processing system.
摘要:
The apparatus and method of the present invention quickly determines the presence of contours in a digital color image by determining the busy and the non-busy (smooth) regions of the original digital color image and determining the luminance variations in the smooth regions of the original digital color image and in a quantized version of the original digital color image. The difference between the luminance variations is compared against a selected threshold value, which if exceeded causes a mark to be associated with the pixel under consideration. For each pixel of the quantized digital color image that is associated with the mark or has a mark associated with a neighboring pixel in a window around the pixel of interest the color of the pixel is selected to minimize and or remove the contour.
摘要:
A color calibration job identification system and method are provided, wherein the job identification data is encoded on a printed page, in a patch code, along with color targets, according to a protocol and format approximately identical to a format of the color targets. The patch code comprises a first portion, including a start code, and a second portion, including job identification data. The first portion of the patch code is comprised of two or more small color patches, each having a predefined color. The second portion of the patch code is comprised of two or more small color patches wherein each of the patches is comprised of a color selected from a plurality of colors, wherein each of the colors is indicative of a unique datum value, preferably an octal digit. The system provides a means for determining correct functioning of a printer and a means for determining an orientation of a printed page in a scanning device.
摘要:
A method of adjusting an image production system to account for a variable property of a desired output medium includes storing a reference characterization of at least one measured value associated with a reference output medium. An output value, adjusted for the variable property of the desired output medium, is determined based on data including the reference characterization of the reference output medium, for example stored in color lookup tables, color rendering dictionaries, or the like. Based on the adjusted output value determined, the desired output medium is then printed or otherwise marked using the output value.
摘要:
A method of color transformation is based on non-separable tiling of a color transformation lookup table. Non-separable tiling allows the lookup table to have fine granularity where it is needed or desired and coarse granularity where it can be tolerated. Therefore, non-separable tiling of the lookup table provides improved transformation quality for a given lookup table size. The non-separable tiles are enumerated. An appropriate tile is selected for use in a color transformation by finding an intersection between lists of tiles associated with each value that comprises a particular pixel. In one embodiment, a tile or transformation rule is associated with bit position in a bit vector. Any particular parameter value may be associated with one or more tiles or transformation rules. Therefore, a particular bit vector associated with a particular parameter value may have a plurality of set bits.