Walter D. Leon-Salas

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An analog-to-digital converter with data compression capabilities is described. By sharing circuits between an integrating converter and a Golomb-Rice encoder it is possible to jointly perform the tasks of quantization and coding. The Golomb-Rice codes are generated during the conversion cycle by employing a shift register and a digital multiplexer. The(More)
An image sensor with joint sensing and energy harvesting functions suitable for outdoor monitoring applications is presented. The image sensor comprises pixels whose photodiodes can be configured either as photosensors to capture images or as tiny solar cells to harvest energy. As more pixels are configured as solar cells, more energy can be harvested from(More)
An analog-to-digital converter suitable for compressive sensing applications is presented. The converter is based on an incremental sigma-delta converter architecture and is able to directly acquire and convert to digital format compressive sensing measurements. A switched-capacitor circuit is proposed for the converter's hardware implementation.(More)
An alternative image decomposition method that exploits prediction via nearby pixels has been integrated on the CMOS image sensor focal plane. The proposed focal plane decomposition is compared to the 2-D discrete wavelet transform (DWT) decomposition commonly used in state of the art compression schemes such as SPIHT and JPEG2000. The method achieves(More)
A CMOS image sensor has been designed to perform the front-end image decomposition in a prediction-SPIHT image compression scheme. The prediction circuitry based on charge sharing is integrated inside the sensor array to perform 3-level image decomposition. A CMOS test chip has been prototyped and tested. The test results justify the pixel design and(More)
A focal plane video compression integrated circuit is presented. The design consists of a 128 times 128 pixel array and a bank of column-level processors. Each one of the column-level processors performs the tasks of image decorrelation, quantization, and entropy encoding. The chip provides at its output a compressed bit stream. The integration of the(More)
An alternative image decomposition method that exploits prediction via nearby pixels has been integrated on a CMOS sensor focal plane. The proposed focal plane decomposition is compared to the 2D discrete wavelet transform (DWT) decomposition commonly used in state of the art compression schemes such as EBCOT and SPIHT. A technique for focal plane(More)
We used Fisher linear discriminant analysis (LDA), static neural networks (NN), and focused time delay neural networks (TDNN) for gesture recognition. Gestures were collected in form of acceleration signals along three axes from six participants. A sports watch containing a 3-axis accelerometer, was worn by the users, who performed four gestures. Each(More)
A radio frequency identification (RFID) sensor for corrosion monitoring in concrete is presented. The sensor can perform linear polarization, open circuit potential, and temperature measurements. The sensor obtains its power from an external RFID reader, which also functions as a datalogger. The sensor's electronic circuit comprises an RFID modem, a(More)