In video processing, a motion compensated process and an equivalent linear process are performed on an input signal, the processing errors of which are computed and compared. The comparison is then used to control a mix between the outputs of the two processes to produce an output signal.

Video signal processing.

A digital automatic gain control apparatus is provided which controls gain such that when an analog video signal is converted into digital signals for processing, the input of the A-D converter is maintained at a fixed level, and after the analog signal has been converted into digital form, the output of the digital system circuit is also maintained at a fixed level. In this apparatus, an input signal is passed through an analog variable gain amplifier, the signal is converted into digital form, and the output of an A-D converter is passed through a digital variable gain amplifier. The amplitude level of the output of the digital variable gain amplifier is detected by an amplitude detecting unit and is controlled so as to be equal to a specified reference value. At this time, the analog variable gain amplifier is controlled so that the level of the control signal for controlling the digital variable gain amplifier is equal to a specified reference value, thereby maintaining the signal of the A-D converter at a fixed level. Gain control of the analog signal system and the digital signal system, before and after the A-D converter, is effected by a single amplitude detecting unit.

Digital automatic gain control apparatus

Digital tuning of a locally generated frequency supplied to a frequency converting mixer, a mobile radio receiver is provided with great economy of components by utilizing the sampling rate oscillator for an analog-to-digital converter provided at the output of an analog intermediate frequency amplifier of the receiver as the source of the difference frequency for a phase locked loop (PLL) for control of the phase of a local oscillator for the mixer or mixers. All frequencies used to supply local oscillations to mixers, as well as the operating frequency of the phase locked loop are integer number multiples of the sampling rate pulse generator. Some division stages have fixed dividers and others have divisors selectable by a tuning processor and in some of the divisor connections it is useful to interpose a fixed or selectable-factor multiplier. A sampling rate of 42.75 MHz is recommended and an intermediate frequency amplifier frequency which is a rational number multiple of 57 kHZ, preferably 10.6875 MHz are similarly recommended.

Radio receiver for mobile reception with sampling rate oscillator frequency being an integer-number multiple of reference oscillation frequency

According to this invention, a sharpness emphasis is carried out by multiplying a sharpness emphasis signal of an original image by a function of a look-up table which is accessed based on an output from an edge detecting filter performing detections, in accordance with only the edge portions of the original image. Since the edge detecting filter for detecting edges of the image is equipped in order to emphasize the sharpness only in the edge portions of the image, it is possible to prevent the image grains from being sharpness-emphasized. In addition, although the edge detecting filter may have a same size of a mask with that of the unsharpness mask, it is possible, if required, to modify freely both sizes of the masks, in order to perform a proper process in accordance with each image variation.

Method and apparatus for emphasizing sharpness of image by detecting the edge portions of the image

A digital camera with video input is disclosed. An image sensor is provided to capture an image and convert the captured image into R/G/B image signals the are processed by a video signal processing unit for being converted into pixel data having a first format. A TV decoder converts input analog video signals into pixel data having a second format. A scaling unit performs aspect ratio processing and zoom/pan function to pixel data. A TV interface unit converts pixel data having the second format into pixel data having the first format for being selectively output to the scaling unit directly and output to the scaling unit after transferring to the video signal processing unit for performing edge enhancement. A compressing and storage unit performs compress operation to the pixel data output from the video signal processing unit and the scaling unit. An USB unit converts pixel data after being compressed into serial data for output.

Digital camera with video input

In a circuit arrangement for deriving digital color signals from an analog television signal by means of an A/D converter, which forms a digital television signal from the analog television signal in synchronism with a clock signal which corresponds to a whole multiple of the line frequency of the television signal, and further by means of a demodulator, a first phase detector, a first phase calculator and a signal generator, which are interconnected in a phase-locked loop, interference-free demodulation of the chrominance signal in the composite television signal is guaranteed, even when the frequency of the clock signal fluctuates, in that the first phase calculator is supplied not only with a color phase signal from the first phase detector but also with a reference phase signal from a reference circuit which is a measure of the frequency difference or phase difference between the clock signal and a reference signal of stable frequency.

Circuit arrangement for deriving digital color signals from an analog television signal

By means of a digital filter, the chrominance signal is separated from the digitized picture signal and is applied to a variable-gain amplifier which is formed by the series arrangement of a shift stage and a multiplier. The two stages are controlled by a control circuit which receives the maximum amplitude value of the color synchronizing signal, obtained in a digital manner. Depending on this amplitude value the position of the chrominance signal is shifted and thereafter multiplied in the multiplier by a factor of, for example, between 0.5 and 1. Acting thus, the gain factor is split into two sub-factors, one of which is an integral power of 2 and in this way the multiplier is utilized in a much more advantageous manner. The amplitude value of the color synchronizing signal is measured before the amplifier, so that the control is a forward control, none of the problems occurring with closed control loops now being present.

Circuit for adjusting the amplitude of a color signal

The invention relates to a circuit arrangement for increasing the resolution of color contours. A slope detector detects the slope of the luminance signal and, when a predetermined slope value is exceeded, produces a detection signal for energizing a counter. The counter controls an edge enhancement circuit for a color difference signal, in which, as soon as the counter is energizing, the value of the color difference signal is stored and is available as an output signal. After a predetermined number of equidistant clock pulses has been counted, the edge enhancement circuit (7, 16) supplies the actual color difference signal value. If before the end of the counting operation, a new detection signal is produced, then the edge enhancement circuit briefly receives and stores the actual color difference signal value, and the counter starts a new counting cycle.

Circuit arrangement for increasing the definition of color contours of a color television signal using selective edge enhancement

In a television receiving section for receiving an analog television signal converted to an intermediate frequency by a mixer (3) and subsequently selected in an intermediate frequency filter (6) which is followed by an A/D converter (7), the intermediate frequency is an integral multiple of the sample clock frequency of the A/D converter (7) for the purpose of simultaneous demodulation of the television signal.

Television receiving section having an a/d converter which simultaneously performs synchronous demodulation

Aus dem digitalisierten Bildsignal wird mittels eines digitalen Filters das Farbartsignal abgetrennt und einem steuerbaren Verstarker zugefuhrt, der aus der Reihenschaltung einer Shift-Stufe und eines Multiplizierers besteht. From the digitized image signal, the chrominance signal is separated by means of a digital filter and fed to a controllable amplifier, which consists of the series connection of a shift step and a multiplier. Beide Stufen werden von einer Steuerschaltung gesteuert, die den auf digitale Weise gewonnenen maximalen Amplitudenwert des Farbsynchronsignals erhalt. Both stages are controlled by a control circuit which receives the recovered digital manner maximum amplitude value of the burst signal. Abhangig von diesem Amplitudenwert wird das Farbartsignal stellenverschoben und anschliesend in einem Multiplizierer mit einem Faktor multipliziert, der beispielsweise zwischen 0,5 und 1 liegt. Depending on this amplitude value of the chrominance signal is shifted filters and then multiplied in a multiplier with a factor which is, for example, between 0.5 and first Auf diese Weise ist der Verstarkungsfaktor in zwei Teilfaktoren zerlegt, von denen der eine eine ganzzahlige Potenz von 2 ist, und damit wird der Multiplizierer sehr viel gunstiger ausgenutzt. In this way, the gain is divided into two factors, one of which is a an integral power of 2, and thus the multiplier is used much more affordable. Der Amplitudenwert des Farbsynchronsignals wird vor dem Verstarker ermittelt, so das es sich um eine Vorwartssteuerung handelt, bei der keine der bei geschlossenen Regelschleifen auftretenden Probleme vorhanden sind. The amplitude value of the burst signal is determined before the amplifier, so that it is a forward control in which none of the problems associated with closed control loops are present.

Jürgen Ruprecht

Papers

Circuit arrangement for deriving digital color signals from an analog television signal

Circuit for adjusting the amplitude of a color signal

Circuit arrangement for increasing the definition of color contours of a color television signal using selective edge enhancement

Television receiving section having an a/d converter which simultaneously performs synchronous demodulation

Circuit for adjusting the colour signal amplitude