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Dark-frame subtraction

About: Dark-frame subtraction is a research topic. Over the lifetime, 1216 publications have been published within this topic receiving 20763 citations.


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Patent
26 Jan 2001
TL;DR: In this article, the authors proposed a data processing method that can detect dark debris without interference by background noise in a fixed star tracking mode suitable to a wide-ranging observation, where an arbitrary point P0 on an image, a point P1 where an object of observation point-imaged at an exposure start time is imaged at exposure end time is computed, and an image output on a line joining the points P0 to P1 on image data is added.
Abstract: PROBLEM TO BE SOLVED: To provide a data processing method that can detect dark debris without interference by background noise in a fixed star tracking mode suitable to a wide-ranging observation. SOLUTION: For an arbitrary point P0 on an image, a point P1 where an object of observation point-imaged at an exposure start time is imaged at an exposure end time is computed, and an image output on a line joining the points P0 to P1 on image data is added. This process is carried out for every point in the image. Before the addition of the image data on the line joining the points P0 to P1, a level of noise is determined, and a high-density image of a celestial body in the image data is replaced with the noise level to erase the star image. The noise level may be determined through the computation of a peak value of a histogram of data on the processed region of the image.

8 citations

Patent
10 Feb 2004
TL;DR: In this paper, an apparatus provided with a storage means for storing an input signal and a circuit for detecting the correlation measures the noise amount on the basis of the difference between images with high correlativity in the preceding frame and the succeeding frame.
Abstract: PROBLEM TO BE SOLVED: To solve a problem that it is difficult to accurately measure a noise amount because the noise and a motion reflect in a calculated value based on a difference between a preceding frame and a succeeding frame in the case of measuring the noise amount of a video signal within a video region. SOLUTION: An apparatus provided with a storage means for storing an input signal and a circuit for detecting the correlation measures the noise amount on the basis of the difference between images with high correlativity in the preceding frame and the succeeding frame. Since wrong measurement due to the motion can be prevented thereby, the noise measurement accuracy is improved. Further, since the noise amount can be measured with high accuracy, it is possible to properly adjust the noise reduction effect. COPYRIGHT: (C)2005,JPO&NCIPI

7 citations

Proceedings ArticleDOI
23 Jan 2015
TL;DR: The experiment shows that the noise simulated by technology is lifelike, and the system cost of the technology is little, which provides a practical engineering train of thought for development of dynamic 3D IR scene.
Abstract: Simulation of IR detector noise is a difficult part in engineering development of 3D dynamic IR scene simulation A technology of dynamically generating noise of IR detector is provided in this article First, by computing and analyzing the images sequence of IR detector, the random gauss noise, salt noise and heterogeneity noise is picked up In scene simulation developed by OSG, a noise "screen" is attached to the view of the simulation scene by technology of refer to texture (RTT), and the image of the heterogeneity noise is made as the RTT texture To realize the dynamic effect, the random gauss noise is generated and rendered by shader base on GPU The salt noise is directly rendered according to the sign of blind pixels in RTT texture The experiment shows that the noise simulated by technology in this article is lifelike, and the system cost of the technology is little The method in this paper provides a practical engineering train of thought for development of dynamic 3D IR scene

7 citations

Proceedings ArticleDOI
TL;DR: In this article, the authors proposed a method to correct the nonuniformity of the dark current at relatively high temperatures for charge-coupled device (CCD) images when dark frames cannot be obtained on the telescope.
Abstract: We have developed a new method to correct dark current at relatively high temperatures for Charge-Coupled Device (CCD) images when dark frames cannot be obtained on the telescope. For images taken with the Antarctic Survey Telescopes (AST3) in 2012, due to the low cooling efficiency, the median CCD temperature was -46°C, resulting in a high dark current level of about 3e−/pix/sec, even comparable to the sky brightness (10e−/pix/sec). If not corrected, the nonuniformity of the dark current could even overweight the photon noise of the sky background. However, dark frames could not be obtained during the observing season because the camera was operated in frame-transfer mode without a shutter, and the telescope was unattended in winter. Here we present an alternative, but simple and effective method to derive the dark current frame from the scientific images. Then we can scale this dark frame to the temperature at which the scientific images were taken, and apply the dark frame corrections to the scientific images. We have applied this method to the AST3 data, and demonstrated that it can reduce the noise to a level roughly as low as the photon noise of the sky brightness, solving the high noise problem and improving the photometric precision. This method will also be helpful for other projects that suffer from similar issues.

7 citations

Journal ArticleDOI
S. Rajkumar1, G. Malathi1
TL;DR: A hybrid statistical noise suppression technique has been developed for improving the quality of the impulse noisy color images and the performance of the proposed image enhancement scheme is proved using the advanced performance metrics.
Abstract: Image noise is one of the key issues in image processing applications today. The noise will affect the quality of the image and thus degrades the actual information of the image. Visual quality is the prerequisite for many imagery applications such as remote sensing. In recent years, the significance of noise assessment and the recovery of noisy images are increasing. The impulse noise is characterized by replacing a portion of an image’s pixel values with random values Such noise can be introduced due to transmission errors. Accordingly, this paper focuses on the effect of visual quality of the image due to impulse noise during the transmission of images. In this paper, a hybrid statistical noise suppression technique has been developed for improving the quality of the impulse noisy color images. We further proved the performance of the proposed image enhancement scheme using the advanced performance metrics.

7 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20238
202221
20213
20202
20192
20187