Types of Histograms

Comb

Histogram combing is a phenomenon that digital photographers want to avoid whenever possible. Histogram combing occurs when an already processed file is adjusted. This phenomenon is one way to illustrate how important it is to use a calibrated and profiled monitor to edit Raw files you plan to send to a lab for printing.

Dog Food

The dog food distribution is missing something—results near the average. If a customer receives this kind of distribution, someone else is receiving a heart cut, and the customer is left with the “dog food,” the odds and ends left over after the master’s meal.

Double-Peaked or Bimodal

Basically, a bimodal histogram is just a histogram with two obvious relative modes, or data peaks. For example, take a look at the histogram shown to the right (you can click any image in this article for a larger view).

Edge Peak

Likewise the histogram range is measuring the peak to peak jitter. Note that the peak to peak jitter only has meaning when referenced to the total number of measurements included because the random jitter component is unbounded and increases with increasing the number of measurements. In our example the total population is shown in the Number of measurements in the P1 statistics, 1.342376E^6 in Figure 9.

image: asq.org
Normal

Normal. A common pattern is the bell–shaped curve known as the “normal distribution.” In a normal distribution, points are as likely to occur on one side of the average as on the other. Be aware, however, that other distributions look similar to the normal distribution. Statistical calculations must be used to prove a normal distribution.

source: asq.org
Plateau

Histograms A histogram is a specialized type of bar chart. Individual data points are grouped together in classes, so that you can get an idea of how frequently data in each class occur in the data set.

source: skymark.com
image: intelex.name
Skewed

Histogram A in the figure shows an example of data that are skewed to the right. The few larger values bring the mean upwards but don’t really affect the median. So when data are skewed right, the mean is larger than the median.

source: dummies.com
Truncated or Heart-cut

For example, temperature data rounded off to the nearest 0.2 degree would show a comb shape if the bar width for the histogram were 0.1 degree. Truncated or heart-cut. The truncated distribution looks like a normal distribution with the tails cut off.

source: asq.org