Pedro R. Gelabert

Programmable DSP platform for digital still cameras

This paper presents a programmable DSP platform for digital still cameras based on the Texas Instruments TMS320C54x family. One major advantage of this platform is that, after capturing an image from a CCD sensor, processing the raw image, and compressing the image for storage is performed on the digital signal processor (DSP). This provides a short shot-to-shot delay and a high degree of flexibility. The system realized also allows instant viewing and selective storing of captured images. This paper outlines the various processing stages necessary to take the raw CCD data and produce a JPEG compressed bit stream and highlighting the advantages of DSPs for this application. The programmable nature of this platform allows for the exploration of different image processing and compression techniques. The low power nature of the digital signal processor provides long battery life.

A DSP powered solid state audio system

New audio compression algorithms and non-volatile flash memory technology have enabled the creation of portable solid-state personal audio players. This paper presents a low-power portable audio system based on the Texas Instruments TMS320C5000 DSP family. This system is designed to play music and other audio media stored on flash memory cards that can hold over an hour of CD quality music. The flash card provides higher audio quality than a cassette tape, yet is smaller and more durable than a CD. The music or audio material downloaded to the flash is obtained from licensed distributors, either through the Internet or through kiosks setup in retail outlets. All the audio decoding and watermarking required by this system is handled by the TMS320C5000 DSP. System performance characteristics are also presented.

Comparison of fixed-pattern and multiple-pattern structured light imaging systems

We present a quantitative comparison of a fixed-pattern structured light system and a multi-pattern structured light system under varying capture environments. Several factors affect the performance of these systems, which makes the task of a fair comparison a very challenging aspect of this study. We conducted our experiments under controlled environment to enable us to control various system parameters for a fair comparison of these two techniques. We describe our methodology in choosing the system parameters for our study. For this analysis, we used two ground truth models with various depth and spatial variations as well as some smooth regions. These models are representative of two extremes of depth measurement scenarios. We show that multi-pattern approaches can be very accurate in controlled environment in stationary scenes due to high SNR, whereas fixed pattern methods are robust to ambient lighting changes but they have lesser accuracy. Further, in practical applications, we show that the multi-pattern approach has higher spatial and depth resolution when compared to a fixed pattern system.

DLP NIRscan Nano: an ultra-mobile DLP-based near-infrared Bluetooth spectrometer

The DLP NIRscan Nano is an ultra-portable spectrometer evaluation module utilizing DLP technology to meet lower cost, smaller size, and higher performance than traditional architectures. The replacement of a linear array detector with DLP digital micromirror device (DMD) in conjunction with a single point detector adds the functionality of programmable spectral filters and sampling techniques that were not previously available on NIR spectrometers. This paper presents the hardware, software, and optical systems of the DLP NIRscan Nano and its design considerations on the implementation of a DLP-based spectrometer.