Abstract:
An image sequence sensor senses images. To associate a motion vector with an image of the sequence currently being processed, k candidate vectors are generated by adding, to a reference motion vector, respectively k search vectors. Then, a motion vector is selected from among the k candidate vectors as a function of a selection rule. Thereafter, the previous two steps are repeated m times, the reference motion vector being on the one hand, for a first iteration of the first step, an initial reference vector selected from among a set of vectors comprising at least one motion vector associated with a previous processed image and being on the other hand, for the m repetitions of the first step, the motion vector selected in the second step preceding the first step. Then, the vector obtained in the third step is associated with the image currently being processed.
Abstract:
Ambient light is detected by a photodiode circuit by measuring the time taken for a digital output of the photodiode circuit to change state in response to exposure of a photodiode of the photodiode circuit to that ambient light. A nominal time for state change is calculated based on photodiode circuit characteristics. Furthermore, an effective time for the photodiode circuit digital output to change state is determined in a calibration mode where the photodiode has been disconnected and a reference current is applied to the circuit. An illumination value of the detected ambient light is then calculated as a function of: the measured time, the effective time and the nominal time.
Abstract:
A method is provided for reading a captured image, with the captured image comprising at least first and second parts and a border area positioned between the first and second parts. Converted pixels are obtained by applying digital-to-analog conversion to the pixels in the captured image, and the converted pixels corresponding to the border area of the captured image are stored in a buffer. A first set of processed pixels is obtained by applying image processing to the converted pixels corresponding to the first part of the image and to the converted pixels stored in the buffer, and a second set of processed pixels is obtained by applying image processing to the converted pixels corresponding to the second part of the image and to the converted pixels stored in the buffer. A processed image is provided by combining the first and second sets of processed pixels. Also provided is a processing device for reading a captured image.
Abstract:
A frequency-shift modulation device includes an oscillating circuit, a phase-locked loop and a digital frequency modulation circuit. The oscillating circuit is connected to the phase-locked loop in order to produce a fixed-frequency clock signal. This clock signal is used for timing the frequency modulation circuit. A standard model crystal oscillator can be used in the oscillating circuit, given that the RF frequency of a wireless transmission signal which is produced by the modulation device is determined digitally.
Abstract:
The invention provides a demodulation PLL wherein: the first position of a switch, which is controlled by a control circuit, respectively connects the outputs of a mixer and a LP filter to high gain and low gain inputs of an oscillator when frequency signals at the inputs of the mixer have not converged sufficiently, i.e. during the PLLs tuning mode; the second position of the switch respectively connects the outputs of the mixer and the LP filter to the low gain and high gain inputs of the oscillator when the frequency signals at the inputs of the mixer and the signal levels on the input and output of the filter have converged sufficiently, i.e. during the PLLs demodulation mode.
Abstract:
An optical mouse includes an image sensor for providing image data via an analog-to-digital converter to a correlation circuit and a motion estimation circuit to provide output signals representative of motion of the mouse. The output signals may be disabled when the mouse is lifted away from the working surface. This may be achieved by high-pass filtering the signals, summing each frame in a summer to provide a single value, and comparing this to a threshold. If the filtered and summed value exceeds the threshold, this may indicate that the image contains in-focus objects, and that the mouse is on the working surface.
Abstract:
In relation to a current image from a sequence of images captured by an image sensor, in a first step, a temporary motion vector is determined as a function of reference data comprising a preceding image and a motion vector associated to the preceding image. Then, in a second step, if the temporary motion vector does not satisfy a reliability criterion, the first step is repeated in relation to a following image, on the basis of the same reference data. Otherwise, the temporary motion vector is associated with the current image.
Abstract:
A process for determining the displacement of an entity equipped with a sensor for capturing a sequence of images, comprising a step for determining a motion vector associated with a current image as a function of at least one correlation calculation between a first block of pixels in the current image and a second block of pixels from which the vector points towards said first block of pixels, with said second block being in a previous image in the sequence of images, wherein the dimensions of the first block are determined as a function of at least a motion vector associated with a previous image in the image sequence.
Abstract:
A circuit for processing broadcast signals that includes circuitry for receiving and processing broadcast signals which contain audio information and providing a first audio signal, and circuitry for controlling the amplitude of a received second audio signal in response to a first control signal, and providing a third audio signal wherein the circuit further comprises circuitry that receives the first audio signal and provides the second audio signal for automatically limiting the amplitude of the first audio signal in response to at least one reference signal.
Abstract:
A process for determining the displacement of an entity equipped with a sensor for capturing a sequence of images, comprising a step for determining a motion vector associated with a current image as a function of at least one correlation calculation between a first block of pixels in the current image and a second block of pixels from which the vector points towards said first block of pixels, with said second block being in a previous image in the sequence of images, wherein the dimensions of the first block are determined as a function of at least a motion vector associated with a previous image in the image sequence.