Characteristics of an Image Sensor with Early-Vision Processing Fabricated in Standard 0.35 μm Cmos Technology

Jendernalik, W.; Jakusz, J.; Blakiewicz, Grzegorz; Szczepański, S.; Piotrowski, Robert

doi:10.2478/v10178-012-0017-8

Cited by 2 publications

(2 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The PSF-fitting could be used in calculation of stars' centroids in real deep sky images. This method is not time-consuming and is applicable in real-time ASIC or FPGA circuits [25][26][27][28][29][30][31][32][33]. Table 2.…”

Section: Calculation Of Stars' Centroids With Psf-fitting and Two Stamentioning

confidence: 99%

Stars’ Centroid Determination Using PSF-Fitting Method

Suszyński

Wawryn

2015

Metrology and Measurement Systems

View full text Add to dashboard Cite

This paper presents an algorithm for restoring telescope images corrupted by turbulence effects and readout noise of a telescope system in order to determine centroid positions of stars, especially the position of a reference star. A computation method employing an accurate centroid estimation algorithm reconstructing a point spread function (PSF) from the recorded astronomical images has been used. Minimisation of turbulence effects and telescope control system noise in long exposure images acquired and recorded by the ground telescope is proposed. As a solution of the distortion error a minimisation signal is dedicated to GoTo calibration procedures built in control mechanisms of the electromechanical telescope system. The proposed method has been verified in the Matlab environment for real deep sky images recorded by the ground telescope system.

show abstract

Section: Calculation Of Stars' Centroids With Psf-fitting and Two Stamentioning

confidence: 99%

Stars’ Centroid Determination Using PSF-Fitting Method

Suszyński

Wawryn

2015

Metrology and Measurement Systems

View full text Add to dashboard Cite

show abstract

“…The contrast and brightness of the images have been increased in order to visualize the FPN noise. The given values of FPN have been calculated using the commonly used definition [21]: FPN = σ(∆n)/n max • 100% = σ(∆n)/2 8 • 100%. Simulations have been carried out for various values of mismatch for specific pixel components.…”

Section: The Impact Of Mismatch On Image Non-uniformitymentioning

confidence: 99%

On analog comparators for CMOS digital pixel applications. A comparative study

Jendernalik

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

View full text Add to dashboard Cite

Abstract. Voltage comparator is the only -apart from the light-to-voltage converter -analog component in the digital CMOS pixel. In this work, the influence of the analog comparator nonidealities on the performance of the digital pixel has been investigated. In particular, two versions of the digital pixel have been designed in 0.35 µm CMOS technology, each using a different type of analog comparator. The properties of both versions have been compared. The first pixel utilizes a differential comparator with the increased size and improved electrical performance. The second structure is based on a very simple non-differential comparator with a reduced size and degraded performance. Theoretical analysis of the comparator nonideality effect on the quality of the image obtained from the digital pixel matrix as well as simulation results are provided.Key words: CMOS image sensor, CMOS digital pixel, analog comparator, fixed pattern noise (FPN). On analog comparators for CMOS digital pixel applications.A comparative study W. JENDERNALIK* Faculty of Electronics Telecommunications and Informatics, Gdańsk University of Technology, 11/12 Narutowicza St., 80-952 Gdańsk, Poland pixels containing a photosensor and a complete A/D converter are larger than 20 µm × 20 µm. This results in degradation of the fill factor, increase of the matrix area, and the increase of the integrated image sensor price. For this reason, development of A/D converter solutions that can be implemented on a small pixel while maintaining sufficiently large bit resolution and high conversion quality becomes of primary importance. One of the most important components of the A/D converter is a CMOS analog voltage comparator. Such a comparator usually consists of a conventional MOS differential pair with a current mirror as an active load, an amplifier stage implemented as a common-source configuration, as well as one or two CMOS inverters which work as an additional amplification stage. The comparator footprint may contribute to as much as 20 to 30 percent of the entire pixel area [7]. In order to reduce the comparator size, one needs to reduce the sizes of its transistors, which leads to degrading the electrical performance of the circuit. Smaller transistor size means larger technological spread of their parameters and the increased offset voltage of the comparator. Moreover, the 1/f noise level is also increased.In this work, we investigate a possibility of applying -in a digital pixel -a simple non-differential analog comparator consisting of four CMOS transistors. Such a comparator is characterized by worse electrical performance compared to a conventional differential comparator; however, it features a considerably smaller footprint. In order to compare the influence of the analog comparator performance on the image quality, two versions of a digital pixel realized in 0.35 µm CMOS technology have been designed. The pixels are only different with respect to the analog comparator. Simulation studies have been performed for the two matrices of the siz...

show abstract

Characteristics of an Image Sensor with Early-Vision Processing Fabricated in Standard 0.35 μm Cmos Technology

Cited by 2 publications

References 23 publications

Stars’ Centroid Determination Using PSF-Fitting Method

Stars’ Centroid Determination Using PSF-Fitting Method

On analog comparators for CMOS digital pixel applications. A comparative study

Contact Info

Product

Resources

About