Algorithms For Adaptive Histogram Equalization

Pizer, Stephen M.; Austin, John D.; Cromartie, Robert; Geselowitz, Ari; Romeny, Bart ter Haar; Zimmerman, John B.; Zuiderveld, Karel J.

doi:10.1117/12.966688

Cited by 6 publications

(3 citation statements)

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“…However, there was some heterogeneity in the intensity of staining between individual mitochondria which made it difficult to set a global intensity threshold without introducing error in the assignment of pixels corresponding to mitochondria, particularly those that were lightly labeled. To compensate for the different levels of labeling of individual mitochondria, the intensity distribution of light from all regions within the image was first adjusted using a locally adaptive histogram equalization algorithm (16). A single global intensity threshold could then be chosen to eliminate most of the nonmitochondrial background without significant loss of mitochondrial regions.…”

Section: Correction For Nonspecific Labelmentioning

confidence: 99%

Modulation of hexokinase association with mitochondria analyzed with quantitative three-dimensional confocal microscopy.

Lynch

Fogarty

Fay

1991

The Journal of Cell Biology

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Abstract. Hexokinase isozyme I is proposed to be associated with mitochondria in vivo. Moreover, it has been suggested that this association is modulated in coordination with changes in cell metabolic state. To test these hypotheses, we analyzed the subcellular distribution of hexokinase relative to mitochondria in paraformaldehyde-fixed astrocytes using immunocytochemistry and quantitative three-dimensional confocal microscopy. Analysis of the extent of colocalization between hexokinase and mitochondria revealed that ,070% of cellular hexokinase is associated with mitochondria under basal metabolic conditions. In contrast to the immunocytochemical studies, between 15 to 40% of cellular hexokinase was found to be associated with mitochondria after fractionation of astrocyte cultures depending on the exact fractionation conditions.The discrepancy between fractionation studies and those based on imaging of distributions in fixed cells indicates the usefulness of using techniques that can evaluate the distributions of "cytosolic" enzymes in cells whose subcellular ultrastructure is not severely disrupted. To determine if hexokinase distribution is modulated in concert with changes in cell metabolism, the localization of hexokinase with mitochondria was evaluated after inhibition of glucose metabolism with 2-deoxyglucose. After incubation with 2-deoxyglucose there was an approximate 35 % decrease in the amount of hexokinase associated with mitochondria. These findings support the hypothesis that hexokinase is bound to mitochondria in rat brain astrocytes in vivo, and that this association is sensitive to cell metabolic state. HEXOK INASE I is the primary isoform of hexokinase found in brain (21), and a number of insulin-sensitive tissues (2,18,20) and tumorigenic cells (14,17). The majority of this hexokinase appears to be associated with mitochondria in many of these cell types. Although up to 85 % of brain hexokinase can be associated with mitochondria after tissue fractionation, it has been suggested that only a small amount of hexokinase is associated with mitochondria in astrocytes (11). When associated with mitochondria, the affinity of the enzyme for one of its substrates (ATP) is elevated, and sensitivity to inhibition by its product glucose-6-phosphate (G-6-P)' is lowered (23). Thus, the interaction of hexokinase I with mitochondria is proposed to be kinetically advantageous. Furthermore, the association of hexokinase with mitochondria is proposed to be regulated in vivo. This hypothesis is based on the observation that the interaction of hexokinase with mitochondria is sensitive to the concentrations of several ions and metabolites. The principal modulator of hexokinase binding to mitochondria may be G-6-P, since this metabolite will release hexokinase from isolated mitochondria (17,23). This effect of G-6-P is counteracted by physiological levels of inorganic phosphate. From 1. Abbreviations used in this paper: G-6-P, glucose-6-phosphate; MITO IMP, inner mitochondrial membrane epitope; 2DG, 2-deoxyglucose...

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Section: Correction For Nonspecific Labelmentioning

confidence: 99%

Modulation of hexokinase association with mitochondria analyzed with quantitative three-dimensional confocal microscopy.

Lynch

Fogarty

Fay

1991

The Journal of Cell Biology

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“…Histogram equalization is a widely used method in image contrast enhancement [ 44 ]. The basic idea behind this method is to redistribute all pixel values to be as close as possible to a specified desired histogram.…”

Section: Methodologiesmentioning

confidence: 99%

Lane Marking Detection and Reconstruction with Line-Scan Imaging Data

Luo

Wang

2018

Sensors

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Lane marking detection and localization are crucial for autonomous driving and lane-based pavement surveys. Numerous studies have been done to detect and locate lane markings with the purpose of advanced driver assistance systems, in which image data are usually captured by vision-based cameras. However, a limited number of studies have been done to identify lane markings using high-resolution laser images for road condition evaluation. In this study, the laser images are acquired with a digital highway data vehicle (DHDV). Subsequently, a novel methodology is presented for the automated lane marking identification and reconstruction, and is implemented in four phases: (1) binarization of the laser images with a new threshold method (multi-box segmentation based threshold method); (2) determination of candidate lane markings with closing operations and a marching square algorithm; (3) identification of true lane marking by eliminating false positives (FPs) using a linear support vector machine method; and (4) reconstruction of the damaged and dash lane marking segments to form a continuous lane marking based on the geometry features such as adjacent lane marking location and lane width. Finally, a case study is given to validate effects of the novel methodology. The findings indicate the new strategy is robust in image binarization and lane marking localization. This study would be beneficial in road lane-based pavement condition evaluation such as lane-based rutting measurement and crack classification.

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“…The amplitude of the interpolation artifact is dependent upon the clipping level used when calculating the histogram of the contextual region (Pizer et al 1986). If the grey scale range over a contextual region is small, then the histogram will have a sharp peak over the grey levels making up the region and will be close to zero for other values.…”

Section: Origin Of the Interpolation Artifactmentioning

confidence: 99%

Reduction of interpolation artifacts introduced by moving histogram equalization (MHE) in digital on-line portal images

McGee¹,

Shalev

1993

Phys. Med. Biol.

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Digifal on-line portal imagingpmvides almostreal time images ofpatients undergoing radiation treabnents, and is used to verify treatment field sire and shape, and to achieve greater set-up and treatment accuracy. A major problem with this new modality is the lack of contrast of anatomical smclures due to lhe relatively small differences in allenuation coefficienta of bone and soft tissue. and the large amount of scaler at megavollage photon energies. One solution to this problem is lo process the images using adaptive conlrast enhancement techniques, one example of which is known as moving histogram equalization (ME). A disadvantage of MH6 is that anifacts often appear in the enhanced image, especially in regions of relative uniformity.A technique has been developed to remove these Mifacts while retaining the high c o n m t of the enhanced image using matched Fourier domain filtering techniques. The artifact reduction factor is found to be about 0.6 for a variely of on-line ponal images.

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Algorithms For Adaptive Histogram Equalization

Cited by 6 publications

References 0 publications

Modulation of hexokinase association with mitochondria analyzed with quantitative three-dimensional confocal microscopy.

Modulation of hexokinase association with mitochondria analyzed with quantitative three-dimensional confocal microscopy.

Lane Marking Detection and Reconstruction with Line-Scan Imaging Data

Reduction of interpolation artifacts introduced by moving histogram equalization (MHE) in digital on-line portal images

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