Abstract: A method of displaying an image with a display device having at least one defective display pixel is provided. The method comprises generating first, second, and third sub-frames using image data for the image, information that identifies the at least one defective display pixel, a first pixel offset associated with the second sub-frame, and a sub-pixel offset associated with the third sub-frame, and alternating between displaying the first sub-frame in a first position, displaying the second sub-frame in a second position spatially offset from the first position according to the first pixel offset, and displaying the third sub-frame in a third position spatially offset from the first position and the second position according to the sub-pixel offset.

Abstract: Red-eye correction on a region of a digital image includes adjusting luminance of the region by generating a statistical measure of the luminance in the region, and computing an adjusted luminance based on the statistical measure according to a viewing condition.

Abstract: A method of displaying an image with a display device having a plurality of defective pixels is provided. The method comprises selecting an offset between a first sub-frame and a second sub-frame using information associated with the plurality of defective pixels, generating the first sub-frame and the second sub-frame using image data for the image, adjusting a first sub-frame pixel value in the first sub-frame associated with one of the plurality of defective pixels, and alternating between displaying the first sub-frame in a first position and displaying the second sub-frame in a second position, the second position displaced from the first position by an amount defined by the offset.

Abstract: A system and method automatically detects and corrects the occurrence of red-eye in digital photographs and images without user intervention. The system includes a face recognition and locator engine for locating human faces within the image and for generating a bounding box around each face. A red-eye locator engine analyzes the pixel data for each bounding box and computes one or more predefined metrics. The preferred metrics include color variation, redness, redness variation and glint. The red-eye locator engine also generates one or more detection masks based upon the computed metrics, and searches the detection mask for an occurrence of red-eye. A red-eye correction engine receives the detection mask including the detected occurrences of red-eye, and generates a correction mask. Pixels identified as being occurrences of red-eye are then de-saturated in accordance with the correction mask.

Abstract: A system and method interpolates a full color image from an array of single color sensors. Each sensor measures a single color, e.g., red, green or blue. The measured color values are stored as an array of data. For each data element, a plurality, e.g., four, gradients are computed that specify the color and/or luminance difference along different linear paths extending through the data element. At least some of the gradients are computed using a first order color differential and a second order color or luminance differential along the selected path. One or more gradients are then selected based on a comparison of the gradients to a computed threshold. Using the data elements along the path of the selected gradient or gradients, the missing color values are interpolated. The interpolation algorithm also utilizes first and second order color differentials.

Abstract: A system and method corrects luminance non-uniformity and increases the apparent amplitude resolution of an image generated by a projector. The projector, which has a given number of stated levels, receives input data and projects images based on that input data. To correct luminance non-uniformity, a projector correction look-up table (LUT) is created. The LUT attenuates the displayed image such that the whole image has the same luminance as the dimmest point. Input data received by the projector is modified by correction information containing in the LUT. The projector output is analyzed to identified the number of unique levels that the projector is capable of producing, which may be less than the number of stated levels. A dithering engine modify the corrected image data to increase the projector's amplitude resolution, creating the illusion of the projector having more than the limited number of unique levels identified.

Abstract: A system and method corrects the luminance non-uniformity of an image generating by a projector by generating a correction look-up table (LUT) for the projector. The projector receives input data and projects images based on the input data. The LUT attenuates the displayed image such that the whole image has the same luminance as the dimmest point. Input data received by the projector is modified by the correction information contained LUT, and the “corrected” data is used to run the projector, thereby correcting the non-uniformity in luminance.

Abstract: A system and method interpolates a full color image from an array of single color sensors. Each sensor measures a single color, e.g., red, green or blue. The measured color values are stored as an array of data. For each data element, a plurality, e.g., four, gradients are computed that specify the color and/or luminance difference along different linear paths extending through the data element. At least some of the gradients are computed using a first order color differential and a second order color or luminance differential along the selected path. One or more gradients are then selected based on a comparison of the gradients to a computed threshold. Using the data elements along the path of the selected gradient or gradients, the missing color values are interpolated. The interpolation algorithm also utilizes first and second order color differentials.

Abstract: A method for correcting the tone of an input image for display on a given output device includes the steps of generating a dither template having advantageously more threshold levels than color levels of the input image. A tone characteristic for the output device is determined by comparing actual output pixel values against expected image pixel values. The tone characteristic curve is scaled to correspond with the number of threshold values in the dither template, and is stored in a look-up table having a number of entries corresponding to the number of threshold values in the dither template. The dither template values are fed to the look-up table, which provides an adjusted dither template which reflects the tone correction required to provide an output image free of tone distortion. The adjusted dither template is then normalized in accordance with characteristics of the input and output display devices.

Abstract: A system and method automatically detects and corrects the occurrence of red-eye in digital photographs and images without user intervention. The system includes a face recognition and locator engine for locating human faces within the image and for generating a bounding box around each face. A red-eye locator engine analyzes the pixel data for each bounding box and computes one or more predefined metrics. The preferred metrics include color variation, redness, redness variation and glint. The red-eye locator engine also generates one or more detection masks based upon the computed metrics, and searches the detection mask for an occurrence of red-eye. A red-eye correction engine receives the detection mask including the detected occurrences of red-eye, and generates a correction mask. Pixels identified as being occurrences of red-eye are then de-saturated in accordance with the correction mask.

Abstract: A method of providing conversion from YUV signals to RGB signals includes the steps of determining a correspondence value between each of the Y, U, and V pixel values and the corresponding one of the R, G, and B pixel values. Three tables are generated; a Y table, a U table and a V table. During operation, each table may then be easily accessed by indexing the table with the respective Y, U or V input, to provide R,G,B data. The method may be used in a 64 bit embodiment using two registers or one register. Alternatively, the method may be used in a 32 bit embodiment. The conversion method can easily be augmented to provide color adjustment during conversion without any added complexity.

Abstract: A method for detecting an image edge within a dithered image. A pixel within a support region is selected for processing. The differences between pixel values in the region and the selected pixel are computed to form a current difference map. Whether the selected pixel in the region differ by no more than one resolution level from any other pixel of the region is determined from the current difference map. An edge is determined not to exist within the region if the difference map for a region contains no values differing by more than one resolution level. An edge is determined to exist within a region if the difference map for the selected pixel and region contain values differing by more than one resolution level. Alternatively, a difference map for the selected region of support is determined and compared to a table of all possible valid difference maps. If a corresponding difference map is found within the table then an edge does not exist within the presently processed region of support.

Abstract: A method for inverse dithering a dithered image using a filter selected from a set of filters arranged in a preselected order is disclosed. Upon receipt of a selected portion of a dithered image, the selected portion is up-multiplied from a first amplitude resolution to a second amplitude resolution. The up-multiplied dithered image at the second amplitude resolution is then filtered by the selected filter coefficients to generate the inverse dithered image.

Abstract: A method for correcting the tone of an input image for display on a given output device includes the steps of generating a dither template having advantageously more threshold levels than color levels of the input image. A tone characteristic for the output device is determined by comparing actual output pixel values against expected image pixel values. The tone characteristic curve is scaled to correspond with the number of threshold values in the dither template, and is stored in a look-up table having a number of entries corresponding to the number of threshold values in the dither template. The dither template values are fed to the look-up table, which provides an adjusted dither template which reflects the tone correction required to provide an output image free of tone distortion. The adjusted dither template is then normalized in accordance with characteristics of the input and output display devices.

Abstract: A method for selecting a filter from among a plurality of ordered filters within an inverse dithering system is disclosed. In response to receipt of a number of filter parameters associated with the plurality of ordered filters and a selected portion of a dithered image, a determination is made of the region of support for the plurality of filters from the filter parameters. From these regions of support, a lowest ordered filter having a region of support that excludes an image edge in the selected portion of the dithered image is selected.

Abstract: A method of reconstructing an image from a dithered image. A predefined set of filters having different regions of support is established. Each filter is defined by a number of filter coefficients and an impulse response function which defines the filter response for a region of support outside of which the impulse response is zero. Filters are organized according to indexes and this organization represents the order in which the filters are considered during a filter selection process. The filter selection process selects a filter constrained by the rule that the filter selected must only perform low-pass filtering on a region of support that does not contain edges of an image. Due to the organization of the filter set, the filter selection process first selects the largest filter from the filter set that fits within the region about the current processed pixel. If there is an edge of an image within the support region of the first selected filter, the next smaller filter is selected.

Abstract: A method of providing conversion from YUV signals to RGB signals includes the steps of determining a correspondence value between each of the Y. U, and V pixel values and the corresponding one of the R, G, and B pixel values. Three tables are generated; a Y table, a U table and a V table. During operation, each table may then be easily accessed by indexing the table with the respective Y, U or V input, to provide R,G,B data. The method may be used in a 64 bit embodiment using two registers or one register. Alternatively, the method may be used in a 32 bit embodiment. The conversion method can easily be augmented to provide color adjustment during conversion without any added complexity.

Abstract: A method and apparatus for inverse dithering a dithered image is disclosed. The system includes a plurality of digital filters which are organized according to a preselected order. A selection module enables the selection of one filter from the plurality of filters according to the preselected order to filter a presently selected portion of the dithered image. The selected portion of the dithered image is then processed based upon the selected filter to generate a portion of the inverse dithered image.

Abstract: A method for bit-depth increasing digital data represented by a first number of original bits which are sequentially ordered beginning with a start bit and ending with an end bit. To bit-depth increase the data, in an expanded presentation, the original bits are replicated in the sequential order starting with the start bit to form replication bits. The original bits are appended with a second number of the replication bits to form the expanded presentation of the digital data. The appended replication bits start with the start bit and are in the sequential order of the original bits.

Abstract: A method of providing conversion from YUV signals to RGB signals includes the steps of determining a correspondence value between each of the Y, U, and V pixel values and the corresponding one of the R, G, and B pixel values. Three tables are generated; a Y table, a U table and a V table. During operation, each table may then be easily accessed by indexing the table with the respective Y, U or V input, to provide R,G,B data. The method may be used in a 64 bit embodiment using two registers or one register. Alternatively, the method may be used in a 32 bit embodiment. The conversion method can easily be augmented to provide color adjustment during conversion without any added complexity.