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.

Improving sensor noise analysis for CT-Scanner identification

Abstract: CT-Scanner devices produce three-dimensional images of the internal structure of the body. In this paper, we propose a method that is based on the analysis of sensor noise to identify the CT-Scanner device. For each CT-scanner we built a reference pattern noise and a correlation map from its slices. Finally, we can correlate any test slice with the reference pattern noise of each device according to its correlation map. This correlation map gives a weighting for each pixel regarding its position in the reference pattern noise. We used a wavelet-based Wiener filter and an edge detection method to extract the noise from a slice. Experiments were applied on three CT-Scanners with 40 3D images, including 3600 slices, and we demonstrate that we are able to identify each CT-Scanner separately.

Memory efficient noise reduction in in-line Fresnel digital holography

Abstract: We discuss some common sources of noise which affect the quality of reconstruction in digital holography. We show that by using holograms obtained with independent illumination patterns, we can suppress these noise sources in a unified manner and improve the image quality while reducing the memory usage.

Restoration of images corrupted with blur and impulse noise

Abstract: Image restoration degraded observation has been a long standing problem in image processing. Number of techniques has been proposed in the past to encounter such problems. Image deblurring in the presence of impulse noise has been discussed here. We propose a two phase approach for restoration of images degraded due to blur and impuse noise. In the first phase, a novel detection method is proposed to findout the pixels which are affected by noise. Then the noisy pixels are filtered out. The filtered data is then used for deblurring in the second phase. In the second phase, a new regularization technique is applied to handle the outliers, which still remains after first phase. Simulation results are shown to validate the proposed method.

Noise analyzing and processing for scientific grade CCD camera

Abstract: In order to reduce the noise of scientific grade CCD camera and improve the image quality,a practical noise restrain circuit and noise processing circuit have been designed in accordance with noise sources and noise-producing mechanisms.These circuits are used in a self-developed scientific grade CCD camera with the DALSA IL-E2 TDI-CCD imager,which have effectively reduced the dark current noise and eliminated the impact of reset noise on useful signals.Thus the imaging quality of the camera is improved.At last,it verifies the conclusion that output S/N of scientific grade CCD camera signal can attain to 50 dB.

Method for Improving Image Quality of Ultrasonic Image, Ultrasonic Diagnosis Device, and Program for Improving Image Quality

Abstract: An ultrasonic diagnosis device in which image quality degradation factors such as a flicker of noise is suppressed after storing signal components. In the ultrasonic diagnosis device, an input image is separated into a signal component image and a noise component image and, after a frame synthesis process is performed on the noise component image, the signal component image and the noise component image on which the frame synthesis process has been performed are synthesized, whereby noise is suppressed. Alternatively, after the input image is separated into the signal component image and the noise component image, the frame synthesis process is performed on the signal component image and then the noise component image and the signal component image on which the frame synthesis process has been performed are synthesized, whereby signal visibility can be improved.