histogram

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histogram

[′his·tə‚gram]
(statistics)
A graphical representation of a distribution function by means of rectangles whose widths represent intervals into which the range of observed values is divided and whose heights represent the number of observations occurring in each interval.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
Fig. 13 Histogram. A diagrammatic representation (f=frequency) of a frequency distribution, consisting of contiguous rectangles, in which the width of each rectangle is proportional to the class interval under consideration and the area of each rectangle is proportional to the associated frequency.

histogram

a diagrammatic representation of a FREQUENCY DISTRIBUTION, consisting of contiguous rectangles displaying interval-level data (see CRITERIA AND LEVELS OF MEASUREMENT) grouped into categories. In a histogram the width of the rectangle is proportional to the class interval under consideration, and the height is the associated frequency. The area of each bar is then proportional to the frequencies for each class interval (see Fig. 13). A histogram differs from a BAR CHART in that it is the areas of the rectangles which represent the relative frequencies.
Collins Dictionary of Sociology, 3rd ed. © HarperCollins Publishers 2000
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Histogram

a column diagram, a type of graphical representation of the statistical distributions of some quantities in quantitative terms. A histogram represents a set of contiguous rectangles constructed on a straight line. The area of each rectangle is proportional to the frequency with which the given quantity is found in the set being studied. For instance, let the measurement of the trunk diameters of 624 pine trees produce the following results:

 Diameter (cm)............... 14-22 22-30 30-38 38-62 No. of trunks 57 232 212 123

The limits of the groups into which the trunks are divided by diameter are plotted along the horizontal axis, and on the segment corresponding to each group, a rectangle having an area proportional to the number of trunks within the given group is constructed as if on a foundation (Figure 1).

The granulometric composition of rocks is often depicted in the form of a histogram. In this case the percent content of the obtained groups of particles of so-called fractions is plotted on the vertical axis and the logarithms of their limiting

Figure 1

size are plotted on the horizontal axis (Figure 2). The use of logarithms is necessitated by the fact that in granulometric analysis, the particles are subdivided into fractions whose size diminishes in a geometric progression. Histograms are

Figure 2

occasionally constructed on arbitrarily chosen equal segments, regardless of the difference in the limiting size of the fractions. Then the heights of the columns are proportional to the content of the fraction sizes.

histogram

A bar graph that uses the width of the bars to represent the various classes and the height of the bars to represent their relative frequencies.

Camera Histograms
Digital camera histograms show the image's overall exposure. Using 256 vertical bars to represent brightness levels from 0 to 255, the leftmost bar is the darkest pixel level (0), and the rightmost bar is the lightest (255). The height of the bars represents the total number of pixels at that brightness level.

What is of most interest to the photographer is how the bars spread horizontally from left to right. For example, if there are no bars on the left, there are no black pixels in the image.

Light Pixels Histograms appear on the same LCD screen used to preview the image. In this daylight example, there is an absence of dark shadows because the histogram shows no pixels on the left side (dark side).

Dark Pixels In this example, the camera was pointed into a totally dark room, and the bars are confined entirely to the leftmost side (dark side).
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
where [E.sub.m,n] is an Dual-LBP code at a center point (m, n), [M.sub.m,n] is the value of the aggregated histogram map at the center point, and [mathematical expression not reproducible] is the pth neighboring value of the center point.
Next we get the statistic histogram for each sub-region and afterward connect every one of the histograms together to acquire a vast histogram arrangement as psoriasis lesion features for classification.
The previous research using texture information focuses on the invariance of the positions of the unevenness of the hue histogram. Figure 5 shows the invariance of the positions of the unevenness of the hue histogram for each change.
In addition to histogram segmentation (i.e., BBHE, DSIHE, RSIHE, etc.), in order to improve HE, histogram clipping also has been developed.
The present study identified that several ADC histogram parameters were associated with volume-based metabolic PET parameters, namely, MTV and TLG.
Rizve, "Block based histogram feature extraction method for bleeding detection in wireless capsule endoscopy," in TENCON 2015 - 2015 IEEE Region 10 Conference, pp.
After applying the same methodology, obtaining the blue histogram, and doing the summation of pixels with the brightness value between 0 and 15, the data shown in Figure 15 was obtained.
(iii) [p.sup.1.sub.i]: the normalized feature, such as HSV histogram from the ith image, 1 [less than or equal to] i [less than or equal to] N, it is a [d.sub.1] -dimensional row vector
A 2D transfer function can then be specified based on the created LH histogram by selecting relevant areas and by assigning them color and opacity.
Here, images can be retrieved using color histogram of images.
As mentioned before, the light source is an important factor and may affect frequency histogram. In this study, all the pictures were taken at the same time, so that the light was same for all photos and also the pictures were free of shadows.

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