Abstract: Techniques for providing a coefficient scaling operational unit to perform the coefficient scaling computation for various image compression schemes are disclosed. To minimize multiple units, each for one image encoding/decoding scheme (e.g., MPEG4 and WMV9), a single coefficient scaling operational unit is designed to accommodate various standards. In one embodiment, the coefficient scaling operational unit comprises an arithmetic logic unit. The arithmetic logic unit operates in accordance with a formula involving multiplication and division. Parameters such as coefficients and quantization parameters are provided to perform the coefficient scaling operation.

Abstract: Techniques for simultaneously and efficiently eliminating echo and noise mixed in voice are disclosed. According to one aspect of the present invention, an adaptive filter system for eliminating noises and echo mixed in voice signal comprises a first signal adaptive filter, a first subtractor, a second adaptive filter and a second subtractor. The first signal adaptive filter estimates the noise mixed in the voice signal according to a reference noise. The first subtractor subtracts the noise estimated by the first adaptive filter from the voice signal to obtain a voice signal without the mixed noise. The second adaptive filter estimates the echo mixed in the voice signal according to a remote voice signal. The second subtractor subtracts the echo estimated by the second adaptive filter from the voice signal without mixed noise to obtain a clean voice signal.

Abstract: Techniques for multiple master devices accessing one or more slave devices via a single data bus are disclosed. According to one aspect of the techniques, a bus controller coupled between the master devices and the slave device, wherein the bus controller is configured to receive bus signals from the master devices, select one of the bus signals from one of the master devices and forwards the selected bus signal to the slave device. After the slave device receives the bus signal from the one of the master devices, the slave device sends a bus response signal to the master devices over the bus controller, and the master device from which the bus signal is selected identifies and receives the bus response signal.

Abstract: Techniques for transmitting data between devices based on two-dimensional symbols are disclosed, where the devices are generally not equipped with the traditional networking capabilities, or at least these traditional networking capabilities are not used for the data communication. According to one aspect of the techniques, two devices communicate with each other by displaying one or more two-dimensional symbols. Data is encoded into one or more symbols that are displayed on one of the devices. Images of the symbols are taken by another one of the devices to receive the data. These images are sequentially processed and decoded so that the data is now received. To accommodate various environments, the system is configured to adjust parameters pertaining to the symbols to achieve an optimum transmission rate.

Abstract: Architecture of an integrated image sensor is disclosed. The image sensor includes an interface to transport image data out of the sensor directly to a host computing device. To accommodate the required data transfer speed, a raw image (e.g., a Bayer pattern image) from the sensor is directly digitized, compressed if the resolution thereof exceeds a range, and output via the interface. A color image of the scene is reconstructed from the raw image in the host computing device.

Abstract: Techniques for simultaneously and efficiently eliminating echo and noise mixed in voice are disclosed. According to one aspect of the present invention, an adaptive filter system for eliminating noises and echo mixed in voice signal comprises a first signal adaptive filter, a first subtractor, a second adaptive filter and a second subtractor. The first signal adaptive filter estimates the noise mixed in the voice signal according to a reference noise. The first subtractor subtracts the noise estimated by the first adaptive filter from the voice signal to obtain a voice signal without the mixed noise. The second adaptive filter estimates the echo mixed in the voice signal according to a remote voice signal. The second subtractor subtracts the echo estimated by the second adaptive filter from the voice signal without mixed noise to obtain a clean voice signal.

Abstract: Techniques for providing a coefficient scaling operational unit to perform the coefficient scaling computation for various image compression schemes are disclosed. To minimize multiple units, each for one image encoding/decoding scheme (e.g., MPEG4 and WMV9), a single coefficient scaling operational unit is designed to accommodate various standards. In one embodiment, the coefficient scaling operational unit comprises an arithmetic logic unit. The arithmetic logic unit operates in accordance with a formula involving multiplication and division. Parameters such as coefficients and quantization parameters are provided to perform the coefficient scaling operation.

Abstract: Techniques for transmitting data between devices based on two-dimensional symbols are disclosed, where the devices are generally not equipped with the traditional networking capabilities, or at least these traditional networking capabilities are not used for the data communication. According to one aspect of the techniques, two devices communicate with each other by displaying one or more two-dimensional symbols. Data is encoded into one or more symbols that are displayed on one of the devices. Images of the symbols are taken by another one of the devices to receive the data. These images are sequentially processed and decoded so that the data is now received. To accommodate various environments, the system is configured to adjust parameters pertaining to the symbols to achieve an optimum transmission rate.

Abstract: Techniques for multiple master devices accessing one or more slave devices via a single data bus are disclosed. According to one aspect of the techniques, a bus controller coupled between the master devices and the slave device, wherein the bus controller is configured to receive bus signals from the master devices, select one of the bus signals from one of the master devices and forwards the selected bus signal to the slave device. After the slave device receives the bus signal from the one of the master devices, the slave device sends a bus response signal to the master devices over the bus controller, and the master device from which the bus signal is selected identifies and receives the bus response signal.

Abstract: An architecture for a digital pixel sensor is disclosed in which the dynamic range of the sensor is increased by taking samples of a subject to be recorded, where each sample is taken over an interval of a different duration than the other samples. In the preferred embodiment of the invention, an array of pixel elements is fabricated in an integrated circuit. Each of the pixel elements outputs a digital signal and comprises a photodetector and an analog to digital converter. The photodetector is integrated with the analog to digital converter. An array of threshold memory cells, each corresponding to one of the pixel elements, is also provided. An array of time memory cells, each corresponding to one of the pixel elements, establishes a different sampling time for each of the pixel elements for each of multiple samples. An array of memory elements, each coupled to one of the pixel elements, is also provided. The memory elements are also fabricated in the integrated circuit.

Abstract: An improved technique for updating a memory in digital pixel sensors in which a memory update may be directed to only some of the locations or cells in the memory is disclosed. According to one embodiment, a multiplex scheme is employed, in which a threshold memory identifies the locations within a row of memory that are to be updated. Data are first read out of a row of memory to be updated. The data are copied to a first buffer or other short term storage area within the digital pixel sensor. New data from the sensor portion of the digital pixel sensor to be written to the memory are stored in a second buffer. The contents of the threshold memory are then applied to a select input of a multiplexer, where the contents of the first and second buffers comprise first and second data inputs to the multiplexer. Thus, the output of the multiplexer comprises an updated row of memory in which only those locations that are to be updated have been changed.

Abstract: A method of optimizing the exposure times of regions of pixels of an image sensor array during exposure is accomplished by utilizing time interval sampling of an image sensor array comprising of pixels configured to generate digital image signals. Luminance values are extracted from each digital image signal and analyzed to determine if a pixel has reached the optimal exposure. If a pixel has reached the optimal exposure, subsequent digital image signals from this pixel will not be recorded. This preserves the recording of the optimal digital image signal generated by the pixel at the time when the pixel reached its optimal exposure. This process of selectively terminating the recording of digital image signals based on optimal exposures of the pixels can be performed on individual pixels or can be performed on a region of pixels.

Abstract: The invention relates to a CMOS image sensor that an be embedded in portable imaging systems. This high spatial resolution and low bit resolution CMOS area image sensor not only enables portable imaging systems such as cellular fax phone, portable copy machines, barcode reader, but also it can be fabricated in standard digital CMOS processes, particularly at 0.35 micron and below. This invention also discloses several portable imaging systems using such a CMOS image sensor. This invention further discloses a CMOS image sensor that has variable spatial resolution and bit resolution. Starting as a high spatial resolution low-bit resolution image sensor, the high bit-resolution is achieved by combining information from a group of nearest-neighbor pixels into a single super-pixel via spatial oversampling. This variable CMOS image sensor can be used in a multiple function imaging device for both document and video imaging, or photography.

Abstract: The invention relates to a CMOS image sensor that can be embedded in portable imaging systems. This high spatial resolution and low bit resolution CMOS area image sensor not only enables portable imaging systems such as cellular fax phone, portable copy machines, barcode reader, but also it can be fabricated in standard digital CMOS processes, particularly at 0.35 micron and below. This invention also discloses several portable imaging systems using such a CMOS image sensor. This invention further discloses a CMOS image sensor that has variable spatial resolution and bit resolution. Starting as a high spatial resolution low-bit resolution image sensor, the high bit-resolution is achieved by combining information from a group of nearest-neighbor pixels into a single super-pixel via spatial oversampling. This variable CMOS image sensor can be used in a multiple function imaging device for both document and video imaging, or photography.

Abstract: An architecture for a digital pixel sensor is disclosed in which the dynamic range of the sensor is increased by taking samples of a subject to be recorded, where each sample is taken over an interval of a different duration than the other samples. In the preferred embodiment of the invention, an array of pixel elements is fabricated in an integrated circuit that also includes a memory space for storing selectively digital signals of the samples from the digital elements.

Abstract: An improved technique for updating a memory in digital pixel sensors in which a memory update may be directed to only some of the locations or cells in the memory is disclosed. According to one embodiment, a multiplex scheme is employed, in which a threshold memory identifies the locations within a row of memory that are to be updated. Data are first read out of a row of memory to be updated. The data are copied to a first buffer or other short term storage area within the digital pixel sensor. New data from the sensor portion of the digital pixel sensor to be written to the memory are stored in a second buffer. The contents of the threshold memory are then applied to a select input of a multiplexer, where the contents of the first and second buffers comprise first and second data inputs to the multiplexer. Thus, the output of the multiplexer comprises an updated row of memory in which only those locations that are to be updated have been changed.