DocumentCode :
3255065
Title :
Mixed-signal CMOS wavelet compression imager architecture
Author :
Olyaei, Ashkan ; Genov, Roman
Author_Institution :
Dept. of Electr. & Comput. Eng., Toronto Univ., Ont.
fYear :
2005
fDate :
7-10 Aug. 2005
Firstpage :
1267
Abstract :
The CMOS imager architecture implements DeltaSigma-modulated block matrix transforms, such as Haar wavelet transform, on the focal plane, for real-time video compression. The active pixel array is integrated with a bank of column-parallel first-order incremental oversampling analog-to-digital converters (ADCs). Each ADC performs column-wise distributed focal-plane sampling and concurrent signed weighted average quantization, realizing a one-dimensional spatial filter. A digital delay and adder loop performs spatial accumulation over multiple adjacent ADC outputs. This amounts to computing a two-dimensional block matrix transform, with no overhead in time and negligent overhead in area compared to a baseline digital imager system. The architecture is experimentally validated on a 0.35 micron CMOS prototype with a bank of first-order incremental oversampling ADCs computing Haar wavelet transform of an emulated pixel array output. The architecture yields simulated computational throughput of 1.4 GMACS with SVGA imager resolution at 30 frames per second
Keywords :
CMOS image sensors; Haar transforms; analogue-digital conversion; data compression; focal planes; integrated circuit design; mixed analogue-digital integrated circuits; spatial filters; video coding; wavelet transforms; 0.35 micron; 1D spatial filter; DeltaSigma modulation; Haar wavelet transform; SVGA imager; active pixel array; block matrix transform; concurrent signed weighted average quantization; focal-plane sampling; mixed-signal CMOS; oversampling analog-to-digital converters; real-time video compression; wavelet compression imager; Added delay; Analog-digital conversion; Computer architecture; Image coding; Image sampling; Matrix converters; Quantization; Spatial filters; Video compression; Wavelet transforms;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Circuits and Systems, 2005. 48th Midwest Symposium on
Conference_Location :
Covington, KY
Print_ISBN :
0-7803-9197-7
Type :
conf
DOI :
10.1109/MWSCAS.2005.1594339
Filename :
1594339
Link To Document :
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