Abstract: A method of reducing artifacts in a digital radiographic image identifies either a row or column direction for the artifacts in the image data as a predominant direction and obtains a measurement of the image data frequency content that is subject to artifacts from the image content according to the predominant direction. The measurement of image data frequency content subject to the artifacts is tested according to a predetermined threshold. Artifacts are reduced when the predetermined threshold is exceeded by generating one or more suppression factors according to the testing results, decomposing the image content into at least two frequency bands in each row and column direction, applying the one or more suppression factors to modify at least one of the frequency bands, and recomposing the image content by recombining the at least one modified frequency band with one or more other bands into which the image had been decomposed.

Abstract: A method for suppressing noise in a diagnostic 3-D image, executed at least in part on a logic processor, captures, at each of a number of projection angles, 2-D image projection data, wherein each 2-D image projection has a central pixel and arranges the 2-D image projection data to form a 3-D data set. Each of the 2-D image projections is processed by performing a diffusion filtering process that obtains a homogeneity value for the 3-D data set, generates a diffusion conductance function according to an intensity gradient between adjacent digital image elements, and applies the diffusion filtering process to digital image elements according to the obtained homogeneity value, the generated diffusion conductance function, and a weighting value that relates to the distance of each pixel in the projection from the central pixel. The diagnostic 3-D image is reconstructed from the processed 2-D image projections.

Abstract: A method for adjusting dot-gain for a halftone binary bitmap file comprises inputting a halftone binary bitmap file consisting of binary pixels (400) to an asymmetric digital filter (500). The binary pixels are filtered with the asymmetric digital filter and generates multi-level pixels (506). The multi-level pixel are compared to a preset level (408) and generates a binary pixel output (410). The binary pixel output is collected and forms an adjusted halftone binary bitmap file (270).

Abstract: An apparatus for imaging a tooth having a light source with a first spectral range and a second spectral range. A polarizing beamsplitter (18) light having a first polarization state toward the tooth and directs light from the tooth having a second polarization state along a return path toward a sensor (68), wherein the first and second polarization states are orthogonal. A first lens (22) in the return path directs image-bearing light from the tooth, through the polarizing beamsplitter (18), toward the sensor (68), and obtains image data from the redirected portion of the light having the second polarization state. A long-pass filter (15) in the return path attenuates light in the second spectral range. Control logic enables the sensor to obtain either the reflectance image or the fluorescence image.

Abstract: A method of reducing artifacts in a digital radiographic image identifies either a row or column direction for the artifacts in the image data as a predominant direction and obtains a measurement of the image data frequency content that is subject to artifacts from the image content according to the predominant direction. The measurement of image data frequency content subject to the artifacts is tested according to a predetermined threshold. Artifacts are reduced when the predetermined threshold is exceeded by generating one or more suppression factors according to the testing results, decomposing the image content into at least two frequency bands in each row and column direction, applying the one or more suppression factors to modify at least one of the frequency bands, and recomposing the image content by recombining the at least one modified frequency band with one or more other bands into which the image had been decomposed.

Abstract: An apparatus for imaging a tooth having a light source with a first spectral range and a second spectral range. A polarizing beamsplitter (18) light having a first polarization state toward the tooth and directs light from the tooth having a second polarization state along a return path toward a sensor (68), wherein the first and second polarization states are orthogonal. A first lens (22) in the return path directs image-bearing light from the tooth, through the polarizing beamsplitter (18), toward the sensor (68), and obtains image data from the redirected portion of the light having the second polarization state. A long-pass filter (15) in the return path attenuates light in the second spectral range. Control logic enables the sensor to obtain either the reflectance image or the fluorescence image.

Abstract: A method for suppressing noise in a diagnostic image executes one or more iterations of segmenting the image to identify and label one or more regions in the image; and performing selective diffusion on at least one of the one or more labeled regions in the image. A homogeneity value is computed for the region. A diffusion conductance function is generated for the region according to an intensity gradient between adjacent digital image elements within the region. The diffusion process is applied to a plurality of digital image elements within the region.

Abstract: A method, and digital capture apparatus for use therewith, is described for correcting a channel dependent color aberration in a digital image, where the digital image is composed of a plurality of color channels. The method includes capturing an image comprising the color channels, where one of the color channels is a blurred color channel due to a channel dependent color aberration affecting that channel. Then, one of the other color channels, other than the blurred color channel, is used as an indication of an aim sharpness, and the sharpness of the blurred color channel is adjusted, at least partially, toward the aim sharpness.

Abstract: A method for displaying live video of a tooth identifies a tooth tissue region in a viewable image frame obtained from a video stream and processes pixel data within the tooth tissue region to identify a suspected caries site. Intensity values for pixels that correspond to the suspected caries site are modified and a highlighted viewable image frame is formed as a combination of the modified intensity values corresponding to the suspected caries site and other pixel values in the viewable image frame. The highlighted viewable image frame is displayed in video form.

Abstract: A method for adjusting dot-gain for a halftone binary bitmap file comprises inputting a halftone binary bitmap file consisting of binary pixels (400) to an asymmetric digital filter (500). The binary pixels are filtered with the asymmetric digital filter and generates multi-level pixels (506). The multi-level pixel are compared to a preset level (408) and generates a binary pixel output (410). The binary pixel output is collected and forms an adjusted halftone binary bitmap file (270).

Abstract: A method is disclosed for processing of images to detect dental caries, that includes the following steps. Directing incident light (16) toward a tooth (20), where this light excites a fluorescent emission from the tooth. Obtaining a fluorescence image (35) from the fluorescent light component (19), and obtaining a reflectance image (34) from the back-scattered light (18) from the tooth. Applying a color balance operation to the reflectance image. Removing the specular reflectance components from the color balanced reflectance image (82) to give a back-scattered reflectance image (50). Registering the fluorescent image with the back-scattered reflectance image. Combining the registered fluorescent image (115) with the back-scattered reflectance image to provide a diagnostic image (52).

Abstract: A method for converting an original halftone bitmap image to a color converted halftone bitmap image. A set of asymmetrical morphological filters is provided. The original halftone bitmap image is segmented into blocks and for each block: apply the set of morphological filters to the original halftone bitmap image to produce a set of modified halftone bitmap images; estimate the percent dot area of the original halftone bitmap image and the set of modified halftone bitmap images; a predetermined dot-gain to the percent dot area of the original halftone bitmap image to produce a modified percent dot area; select the modified halftone bitmap image whose percent dot area is closest to the modified percent dot area to produce a block of the color corrected halftone bitmap image; and replace the original halftone bitmap image with the combined blocks of selected modified halftone bitmap image.

Abstract: An apparatus for imaging a tooth having a light source with a first spectral range and a second spectral range. A polarizing beamsplitter (18) light having a first polarization state toward the tooth and directs light from the tooth having a second polarization state along a return path toward a sensor (68), wherein the first and second polarization states are orthogonal. A first lens (22) in the return path directs image-bearing light from the tooth, through the polarizing beamsplitter (18), toward the sensor (68), and obtains image data from the redirected portion of the light having the second polarization state. A long-pass filter (15) in the return path attenuates light in the second spectral range. Control logic enables the sensor to obtain either the reflectance image or the fluorescence image.

Abstract: A method for obtaining an image of a tooth obtains an area image of the tooth (20) surface and identifies a region of interest from the area image by positioning a marker (146) on the area image. The marker (146) corresponds to at least a portion of the region of interest and identifies a scanning area. An optical coherence tomography (OCT) image is then obtained over the scanning area.

Abstract: An apparatus for obtaining an image of a tooth having at least one light source providing incident light having a first spectral range for obtaining a reflectance image (122) from the tooth and a second spectral range for exciting a fluorescence image (120) from the tooth. A polarizing beamsplitter (18) in the path of the incident light from both sources directs light having a first polarization state toward the tooth and directs light from the tooth having a second polarization state along a return path toward a sensor (68), wherein the second polarization state is orthogonal to the first polarization state. A first lens (22) in the return path directs image-bearing light from the tooth toward the sensor (68), and obtains image data from the portion of the light having the second polarization state. A long-pass filter (15) in the return path attenuates light in the second spectral range.

Abstract: A method for color correcting an original halftone bitmap image by a predefined color correction function to produce a color corrected halftone bitmap image comprising: providing an original halftone bitmap image; estimating the dot area percentage of the original halftone bitmap image in a set of sub-image blocks; calculating an aim dot area percentage, based on a predefined color correction function, for each sub-image block in the original halftone bitmap image, calculating the number of halftone bitmap image pixels to convert to on or off states to produce a modified original halftone bitmap image that has the aim dot area percentage where said value is designated by N, for each sub-image block in the original halftone bitmap image, and converting N pixels in the original halftone bitmap image to either on or off states depending on whether the aim dot area percentage is greater or less than the dot area percentage of the original halftone bitmap image respectively, for each sub-image block in the origina

Abstract: A method for improving the wavelength dependent registration of digital images includes the steps of (a) detecting a similar feature in two or more digital records of the same scene, (b) determining from the feature a shift due to misregistration of at least one of the digital records relative to another of the digital records, and (c) processing the shifted digital record(s) with a digital filter having a phase response that compensates for the shift, thereby providing a correction for the wavelength dependent misregistration between the digital records.

Abstract: A method of steganographic encoding data into an image which encoded data is related to image processing functions that may be used to process the image, the method comprises the steps of providing a dispersed message dimension; providing a grid spacing value; providing an array of object identifiers and associated object locations based on the grid spacing value; embedding an object identifer at a first location into the image; embedding a second object identifier at a second location, wherein the the second location is an integer, non-zero multiple of the grid spacing value.

Abstract: A method for modification of metadata in an image processing chain is disclosed. The method comprises the steps of: providing metadata corresponding to characteristics of a specific digital image; generating a metadata transformation related to at least one specific image transformation; and modifying the metadata according to the specific image transformation. The method is implemented in an image reproduction system. The system has an imaging capture device for providing digital image data. The imaging capture device can be for example a film scanner, flat bed scanner, or digital camera. A memory device stores metadata associated with the captured digital image data. The image transformations are carried out by an image processing chain. In addition to that a metadata processing chain is implemented and connected to the image processing chain in cases where the image transformations are metadata sensitive.

Abstract: A method for converting an original halftone bitmap image to a color converted halftone bitmap image by morphological filtering of the original image to compensate for tone and color reproduction characteristics comprising: providing an original halftone bitmap image. The method includes providing a set of asymmetrical morphological filters that have the property that when they are applied recursively in order, the features in the halftone bitmap image are dilated or eroded by varying amounts by extending or reducing the edges first in one direction, then in two directions, etc.