Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Philips Electronics North America Corporation

Haiyan He

Johan Gerard Willem Maria Janssen

Raymond N Veldhuis

Johan Gerard Janssen

Christian Hentschel

An edge detection technique combines a low-pass second derivative of an image signal, a low-pass first derivative of the image signal, and an estimation of edge frequency. The edge frequency estimation is preferably based on a ratio of a third to a first low-pass derivative of image signal. The image signal is preferably a luminance signal.

Method and apparatus for edge detection

Image enhancement is achieved by a combination of linear and non-linear techniques. The linear technique is preferably peaking, while the non-linear techniques is preferably LTI. The peaking is applied to non-edge areas of the image. The LTI is applied to edge areas of the image. LTI is of the sub-pixel variety. The image enhancement device is preferably part of a device for converting standard definition to high definition signals.

Method and apparatus for improving conversion from SD to HDTV

There is disclosed an apparatus for sharpening an edge in a video image. The apparatus comprises: 1) a first circuit for determining a first luminance value of a first pixel associated with the first edge and a second luminance value of a second pixel associated with the first edge, wherein the first and second pixels are adjacent pixels; 2) a second circuit for determining a position of a first subpixel disposed between the first and second pixels, wherein the first subpixel position is disposed approximately at a center of the first edge; 3) a third circuit for increasing a luminance value of a second subpixel disposed on a first side of the first edge center; and 4) a fourth circuit for decreasing a luminance value of a third subpixel disposed on a second side.of the first edge center opposite the first side.

System and method for improving the sharpness of a video image

An apparatus and method is disclosed for measuring and filtering noise signals in an active video signal to create an enhanced video signal that produces a video image that is subjectively perceived to be superior to prior art video images. The apparatus of the invention comprises (1) a filter for filtering frequency components of a video signal, and (2) an absolute value unit for calculating the absolute value of pixels in the filtered video signal, and (3) a clipping unit for clipping the absolute values of the pixels to a threshold value related to subjective human perception abilities, and (4) a summer circuit for summing the values of the clipped signals for pixels that are located within a sliding window, where the sliding window is sequentially located in different areas of a frame of the video image, and (5) a detector for detecting at least one minimum sum of the clipped absolute values of the pixels that is indicative of the noise in the video signal of the video image. The apparatus and method provide ratios of video signal to noise that permit the creation of subjectively superior video images. The apparatus and method also measure blocking artifacts in the video signal.

Subjective noise measurement on active video signal

A method is described for short-time Fourier-converting a speech signal and for resynthesizing an output speech signal from the modulus of its short-time Fourier transform and from an initial phase. In particular, after the Fourier converting the signal is subjected to a phase-specifying operation. Subsequently speech duration is affected by systematically maintaining, periodically repeating or periodically suppressing result intervals of the successive Fourier converting and phase affecting. Finally, a resynthesizing operation is executed. Speech pitch can likewise be affected through systematically excising or inserting signal intervals. Finally, the two strategies can be combined, so that ultimately, pitch and duration can be affected independently from each other.

Growing community of inventors

Wappingers Falls, NY, United States of America

Haiyan He