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.

A local adaptive threshold noise detection linear interpolation filter (LALIF) for stripe noise removal in infrared images

Abstract: Stripe noise is usually introduced into infrared images during acquisition, which seriously deteriorates the image quality and affects the subsequent analysis of the image. In this paper, the spatial mathematic model and the comb-like impulse spectrum characteristics in Fourier domain of stripe noise are given. On this basis, a local adaptive threshold noise detection linear interpolation filter (LALIF) for stripe noise removal in infrared images is designed. In the filter method, the first, we crop the original image into two sub-images with optimal size to make the comb-like impulse spectrum characteristics of the stripe noise most prominent. The second, we use a local adaptive threshold to distinguish noise frequency points from the useful frequency points in the peak regions of the amplitude spectrum, and reassign the value of noise frequency points by linear interpolation. At last, we amalgamate the sub-images to obtain the stripe noise removal image. Experimental results indicate that the proposed method has a good performance in adaptability and stability for complex stripe noise removal in infrared images.

Detection and removal of fixed-valued impulse noise using sparse representations

Abstract: In this paper, a new method to remove salt and pepper noise from an image through sparse representation is proposed. The proposed method consists of two stages. In the first stage, the positions of noise pixels are detected by thresholding the absolute difference between the noisy image and its sparse representation. In the next stage, the pixels that are detected as noisy pixels are removed and then filled using image inpainting through sparse representation. The experimental results show that the proposed filter is suitable for removing impulse noise from an image.

Image sensor including noise removing unit, image pickup device having the image sensor, and image sensing method performed in the image sensor

Abstract: An image sensor including a noise removing unit may sense images accurately by measuring the amount of noise generated when the image sensor does not perform a sensing operation, storing information about the measured noise amount in each pixel, and removing photocharge corresponding to the information about the measured noise amount during image sensing.

Medium Noise Removal Algorithm and Medium Measuring of Fidelity of Image

Abstract: This paper makes a new definition on image noise according to two features of noise known as the random and fuzzy after the analysis of the progress of image noise production.Following that a new image noise removal algorithm based on the measuring of medium truth scale is given.By sample simulation and classical PSNR evaluation,it shows the image noise removal algorithm based on measuring of medium truth scale brings about a better noise removal effect compared with the classic one,which will lead to its practicable and effective applications in noise removal and image restoration.In addition,a new measuring method of fidelity of image based on image entropy is introduced in this paper to reduce the common deviation between the classical assessment results such as PNSR and the human subjective perception as well as its validity is proved by a sample assessment.

Research on CCD Noise Signal Processing

Abstract: In CCD signal acquisition system, reset noise becomes important compared with the other noise sources at high pixel readout frequencies. According to CCD output noise characteristic, the noise transmission function and analysis model are established, the reset noises is tested by using the most suitable CDS technology. Experimental result shows that reset noises is farthest restrained only selecting suitable sampling time.