Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Socionext Inc.

Atsuhisa Kageyama

Minoru Kawabata

Masahiro Takeshima

Hiroko Sugimoto

Toshiaki Tsuji

Katsuya Ishikawa

Hisao Kunitani

Keiichi Ito

Yuki Kakuya

Hidetoshi Suzuki

Kiyoshi Imai

Nobuo Taketani

Satoru Tanigawa

Hideaki Sadamatsu

Shinichi Tomioka

Nobutaka Okada

Akihiro Suzuki

Naoji Okumura

Hiroshi Ando

Hiroki Monta

Shirou Yoshioka

Ryuichi Shibutani

Keiichi Kuzumoto

Toshihiro Matsumura

Masahiro Tani

Hiroshi Sonobe

Hiroshi Taniuchi

Kazutoshi Funahashi

Koichi Inoue

Kazunari Yamaguchi

Shotaro Itakura

Nobuko Fujita

Akihiro Matsushita Electric Ind Co Ltd Suzuki

An image correction device generates a corrected image for a viewer with low vision, by adding excessive emphasis which reduces image quality as perceived by a viewer having normal eyesight, to at least one of luminance gradation, luminance contour, and color tone of a pre-correction image. The image correction device includes: a controller which specifies, in a low vision mode which is an image correction mode for the viewer with low vision, a parameter that represents an amount of correction greater than an upper limit of an amount of correction which does not reduce the image quality as perceived by the viewer having normal eyesight when the pre-correction image is corrected; and an image processor which generates the corrected image by correcting the at least one of the luminance gradation, the luminance contour, and the color tone of the pre-correction image with the amount of correction represented by the parameter.

Image correction device and video content reproduction device

In order to obtain an optimum depth enhancement effect for three-dimensional (3D) images, a depth information extractor configured to compute depth information from an input video signal, a 2D/3D converter configured to convert, when the input video signal is a two-dimensional (2D) video signal, the 2D video signal to a first video signal which is a 3D video signal based on the depth information, a correction factor calculator configured to compute a correction factor based on the depth information, a selector configured to select either the input video signal or the first video signal and output the selected signal, and a contour enhancement processor configured to perform an enhancement process on the output of the selector based on the correction factor and output the enhanced signal as an output video signal are provided.

Video signal processing device

It is determined whether or not an input image is an image converted from an image with a relatively low resolution based on one frame of an image. A resolution determination device includes: an edge strength calculator configured to obtain an edge strength of a pixel included in an input image based on luminance of the pixel and luminance of a pixel adjacent to the pixel, for each of a plurality of pixels included in the input image; and a resolution determiner configured to determine whether or not the input image is an image upconverted from an image with a predetermined resolution or less, based on distribution of the edge strengths.

Resolution determination device, image processor, and image display device

In a semiconductor device of the present invention, a clock is not changed instantaneously but it is changed over maximum N+1/M clocks (N: integer not less than 2) by shifting delay cells in a step by step manner to make the phase state of a previous reference signal and the phase state of a present reference signal coincide with each other, whereby the clock is synchronized with the reference signal with accuracy, and the duty of the output clock is kept constant. With this semiconductor device, it is possible to prevent the duty of the clock from being discontinuous when a signal whose reference signal does not coincide with the clock is inputted and reset is made to a rising edge of this reference signal.

Semiconductor device

A false contour correcting apparatus is capable of removing a false contour in an image based on a digital image signal while avoiding such a side effect caused by false contour correction where noises negatively effecting the display occur on a screen. Therefore, in the false contour correcting apparatus according, a double bit change detection circuit detects as a double bit change a signal value change which is twice a minimum quantization unit in a digital image signal, and outputs a double bit change detection signal representing the position of the double bit change. A signal correction circuit corrects the double bit change in the digital image signal into two one-bit changes on the basis of the double bit change detection signal. Consequently, a false contour corresponding to a portion where the double bit change exists is removed.

False contour correcting apparatus and method

The present invention has an object to provide a gradation correcting apparatus for correcting the gradation of the white side of a video luminance signal. The gradation correcting apparatus is provided with a maximum value detectorfor detecting a maximum value of a luminance signal S, a white comparatorfor comparing the luminance signal S, a maximum luminance value Sdetected by the maximum value detector, and a first white threshold value S, a white linear converterfor performing linear conversion on the luminance signal Son the basis of the maximum luminance value S, the first white threshold value S, and a second white threshold value S, and a white controllerfor correcting the luminance signal Son the basis of the result of the comparison in the white comparator, the output of the white linear converter, and the second white threshold value S

Gradation correcting apparatus gradation correcting method and video display apparatus

This invention provides a data signal extraction apparatus that accurately extracts data from a data signal that is serially transmitted even when phase shift or the like occurs. According to this apparatus, a phase shift amount calculation circuitcalculates a phase shift amount Sthen a correction amount calculation circuitcalculates a correction amount Son the basis of the phase shift amount San extraction interval correction circuitcorrects an extraction interval value Son the basis of the correction amount, and an extraction pulse generation circuitgenerates an extraction pulse Son the basis of a corrected extraction interval value Sthereby extracting data from a binary signal Son the basis of the extraction pulse.

Data signal extraction apparatus

The present invention provides a gradation correction device which can perform gradation correction using digital feedback processing, and furthermore, can control the digital feedback processing with high accuracy. The gradation correction device is provided with a correction gain adjustable amount generation circuit () and a correction gain generation circuit (), and the correction gain adjustable amount generation circuit () obtains a correction gain adjustable amount which is non-linear in relation to a difference S between a reference luminance level Yband a maximum luminance level, and greater gamma correction is carried out as the value of the difference is larger.

Gradation correction apparatus

A luminance signal processing apparatus that detects an average luminance level, adaptively to various video signal formats. This luminance signal processing apparatus includes a window pulse generation unitfor generating a window pulse signal Sthat indicates a period during which a luminance signal of an input video signal is sampled; a luminance value addition unitfor obtaining a total sum of luminance values of the luminance signal in the period indicated by the window pulse signal S; a number-of-pixel addition unitfor obtaining the number of pixels in the period indicated by the window pulse signal S; a bit shift unitfor bit-shifting an output signal of the luminance value addition unitand an output signal of the number-of-pixel addition unit, respectively; and a division unitfor dividing the bit-shifted output signal of the luminance value addition unitby the bit-shifted output signal of the number-of-pixel addition unit, thereby obtaining an average luminance level.

Apparatus for processing luminance signal

A video signal processing apparatus comprises a sub-screen processing integrated circuit for subjecting a sub-screen video signal to scale-down processing to reduce its display region and output the sub-screen video signal, and a main-screen processing integrated circuit comprising: a switching circuit for receiving a main-screen video signal and the scaled-down sub-screen video signal which is outputted from the sub-screen processing integrated circuit, and selecting the main-screen video signal for a main-screen display region while selecting the sub-screen video signal for a sub-screen display region; an A/D conversion circuit for converting the video signal outputted from the switching circuit into a digital video signal; a digital signal processing circuit for digitally processing the digital video signal outputted from the A/D conversion circuit; and a D/A conversion circuit for converting the digitally-processed video signal into an analog video signal. Therefore, the main-screen video signal and the sub-screen video signal can be combined so that these signals are displayed on a single screen, and the circuit scale of the video signal processing apparatus can be minimized.

Video signal processing apparatus

A gradation correction circuit comprises: an arithmetic means ( ) for operating an output value corresponding to each broken point of a broken line in a vertical blanking period; a level detection circuit for identifying a size relation between each broken line point which is an input value corresponding to each broken point and an input video signal, and calculating a difference between the input video signal and each broken line point; and a correction means ( ) for selecting a gradient of the broken line on the basis of the result identified by the level detection circuit , and performing gradation correction of the input video signal on the basis of the selected gradient of the broken line, the output value calculated by the arithmetic means, and the difference calculated by the level detection circuit, wherein the arithmetic means and the correction means share a number of circuits ( ). Therefore, there is provided a gradation correction circuit where video correction with high precision can be realized without using a memory storing a lookup table, or without increasing a circuit scale.

Gradation correction circuit, and &ggr; correction apparatus

An appropriate correction quantity is obtained for a video luminance signal on an individual video basis with a characteristic value, like the maximum or average value, of the luminance signal taken into account, thereby performing gray scale correction more effectively. A dynamic gamma correction apparatus for performing a correction on a video luminance signal includes: a correction start point control section for obtaining a correction start point, which is a lower limit of a given correction range, in accordance with a characteristic value of the luminance signal; a gamma correction quantity calculating section for obtaining a provisional correction quantity for the luminance signal to be corrected using the correction start point and the luminance signal; a gamma correction gain control section for obtaining a gain for the provisional correction quantity in accordance with the characteristic value of the luminance signal; a multiplier for obtaining a product of the provisional correction quantity and the gain as a gamma correction quantity; and an adder for obtaining a sum of the luminance signal and the gamma correction quantity and outputting the sum. The correction start point and the gain for the provisional correction quantity are controllable in accordance with the characteristic value of the luminance signal. Thus, an appropriate gamma correction quantity can be obtained as a final correction quantity.

Dynamic gamma correction apparatus

A contour correction circuit includes a delay circuit for delaying an input video signal, a corrected waveform generating circuit for generating a contour correction signal out of the input video signal, a variable amplifier for controlling an amplitude of the contour correction signal, a contour control circuit for outputting a gain control signal for controlling a gain in the variable amplifier,. and a first adding circuit for adding an output signal of the delay circuit to an output of the amplifier. When an amplitude-change in an edge portion of the input video signal is over a given level, the smaller amount of contour is corrected at the larger amplitude change. Therefore, even if a signal of a high contrast ratio is adjacent to a signal of a low contrast ratio, desirable contour corrections can be provided to respective signal components.

Contour correction circuit and contour correction method

The present invention provides a color difference signal correction apparatus for correcting color difference of parts having no color, particularly white characters, which can make the correction with high accuracy also for images including lightly colored parts. The color difference signal correction apparatus of the present invention comprises a full-wave rectification circuit for full-wave rectifying an input color difference signal (R&minus;Y)a, a full-wave rectification circuit for full-wave rectifying an input color difference signal (B&minus;Y)b, an addition circuit for adding the outputs of the full-wave rectification circuit and the full-wave rectification circuit , an addition circuit for adding a white character slice level signal e and the output of the addition circuit , a luminance signal slice circuit for slicing a luminance signal g with the output of the addition circuit , and an addition circuit for adding the output of the luminance signal slice circuit and the input color difference signal (B&minus;Y)b and outputting the addition result.

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Ibaraki, Japan

Atsuhisa Kageyama