Abstract: A channel is inserted into a sequence of frames for an image, by varying one or more display characteristics across a display in accordance with a spatio-temporal pattern applied to, for example, successive lines of each modified frame. The channel may be employed to watermark the image, and the watermark may be defined as W(x) and its complement [1−W(x)] in counter-phase rotations of successive lines in pairs of frames. The watermark information is applied in relatively still portions of the image with sufficient lightness level. A receiver includes a watermark detector that has a priori information about the watermark. The watermark detector examines specific regions of the displayed image over time, and tests the regions for the watermark during time intervals when the image remains relatively still.

Abstract: A channel is inserted into a sequence of frames for an image, by varying one or more display characteristics of the resulting image across the display in accordance with a spatio-temporal pattern applied to, for example, successive lines of each modified frame. In some cases, a reverse of the pattern is applied to a successive frame, and the frames modified are preferably B-frames if the image may be encoded in accordance with an MPEG standard. The channel may be employed to watermark the image, and the watermark may correspond to the presence of the channel or may be data in accordance with watermark information carried within the channel. For most display devices, display variations are minimized during the design process, but human viewers may still tolerate and accept subtle variations in a displayed image.

Abstract: A method and apparatus for performing image quality assessment that does not require the use or availability of a reference image. The apparatus comprises a vision pre-processor, a virtual reference generator, a virtual distortion generator, and a image quality metric generator. The vision preprocessor performs a vision-like transformation upon an input image sequence to produce a vision energy map. The virtual reference generator operates upon the vision energy map to produce a virtual reference while the virtual distortion generator produces distortion estimates that are used by the virtual reference generator to produce the virtual reference. The virtual distortion and virtual reference are used by the image quality metric generator to produce a image quality metric for the input video sequence without the use of a reference video sequence.

Abstract: A method and apparatus for assessing the visibility of differences between two input signal sequences, e.g., image sequences is disclosed. The apparatus comprises a perceptual metric generator having an input signal processing section, a luminance processing section, a chrominance processing section and a perceptual metric generating section.

Abstract: A video signal to be processed is applied to a non-linear processor having an adjustable gain responsive to a control signal over at least one portion of the amplitude range of the video input signal. A sampling circuit, responsive to the video signal, generates video samples related to the video signal. A control circuit, responsive to the video samples, generates the control signal in accordance with the number of samples in at least a given amplitude range thereby controlling the percentage of samples of a given range in displayed images. Plural control and sampling circuits may be included provide control for white stretch processing, black stretch processing and video mid-point processing for enhancing contrast through out the entire video signal range.

Abstract: An improved method of arrangement for the cells comprising the pixels of a display device wherein each of the pixels includes a brightest cell, a bright cell, a medium cell and a dark cell. The brightest cell and the bright cell are aligned substantially parallel to one the display axes and the bright cell and the dark cell are diagonally aligned with respect to the axes of the dipslay.

Abstract: A video display device may be simulated using a computer and a conventional video image processor. A test image which is an enlarged version of a typical image to appear on the simulated display device is generated. This enlarged test image is then digitally processed to replicate the effects of the various parameters of the display device which affect the image. The processed signal representing the image is then displayed on a test monitor, which is viewed from a distance which is proportional to the degree of enlargement of the test image.