gray_histo_rangegray_histo_rangegray_histo_rangeGrayHistoRangeGrayHistoRange (Operator)

Name

gray_histo_rangegray_histo_rangegray_histo_rangeGrayHistoRangeGrayHistoRange — Calculate the gray value distribution of a single channel image within a certain gray value range.

Signature

Description

gray_histo_rangegray_histo_rangegray_histo_rangeGrayHistoRangeGrayHistoRange calculates the gray value distribution HistoHistoHistoHistohisto of the single channel ImageImageImageImageimage within RegionsRegionsRegionsRegionsregions and the gray value range [MinMinMinMinmin,MaxMaxMaxMaxmax]. The values for MinMinMinMinmin and MaxMaxMaxMaxmax are rounded down to the next integer if the ImageImageImageImageimage is not of type 'real'"real""real""real""real". The gray value range is divided into NumBinsNumBinsNumBinsNumBinsnumBins bins of the same size, which is returned in BinSizeBinSizeBinSizeBinSizebinSize. If a gray value lies between two bins the gray value is assigned to the smaller bin. If the ImageImageImageImageimage is of type 'real'"real""real""real""real" BinSizeBinSizeBinSizeBinSizebinSize = (MaxMaxMaxMaxmax - MinMinMinMinmin) / NumBinsNumBinsNumBinsNumBinsnumBins. If the ImageImageImageImageimage has discrete gray values the size of a bin is computed with BinSizeBinSizeBinSizeBinSizebinSize = (MaxMaxMaxMaxmax - MinMinMinMinmin + 1) / NumBinsNumBinsNumBinsNumBinsnumBins. Since the accuracy of the histogram HistoHistoHistoHistohisto can be adjusted with NumBinsNumBinsNumBinsNumBinsnumBins, the calculation of the gray value histogram with gray_histo_rangegray_histo_rangegray_histo_rangeGrayHistoRangeGrayHistoRange is most useful for images of type 'real'"real""real""real""real" and images of type 'integer'"integer""integer""integer""integer", which have a high bit depth.

Attention

If the ImageImageImageImageimage has discrete gray values the value of BinSizeBinSizeBinSizeBinSizebinSize may cause the following effects: For BinSizeBinSizeBinSizeBinSizebinSize > 1 multiple neighboring gray values are assigned to the same bin. If BinSizeBinSizeBinSizeBinSizebinSize is no integer the gray values are distributed uneven among the bins, e.g., for BinSizeBinSizeBinSizeBinSizebinSize = 1.5 the first and second gray value are assigned to the first bin, the third gray value is assigned to the second bin, and the fourth and fifth gray value are assigned to the third bin. This becomes noticeable in several peeks in the histogram HistoHistoHistoHistohisto. If BinSizeBinSizeBinSizeBinSizebinSize < 1 some classes are not assigned by any gray value, e.g., for BinSizeBinSizeBinSizeBinSizebinSize = 0.5 the first gray value is assigned to the first bin and the second gray value is assigned to the third bin. The histogram HistoHistoHistoHistohisto shows some gaps, which resembles the structure of a comb.

If the ImageImageImageImageimage is of type 'real'"real""real""real""real" and MinMinMinMinmin = MaxMaxMaxMaxmax, all pixels of the corresponding gray value are assigned only to the first bin.

Parallelization

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Automatically parallelized on internal data level.

Parameters

Result

If the parameters are valid, the operator gray_histo_rangegray_histo_rangegray_histo_rangeGrayHistoRangeGrayHistoRange returns the value 2 (H_MSG_TRUE). If necessary an exception is raised.

Possible Predecessors

min_max_graymin_max_graymin_max_grayMinMaxGrayMinMaxGray

Possible Successors

create_funct_1d_arraycreate_funct_1d_arraycreate_funct_1d_arrayCreateFunct1dArrayCreateFunct1dArray

Alternatives

gray_histogray_histogray_histoGrayHistoGrayHisto, gray_histo_absgray_histo_absgray_histo_absGrayHistoAbsGrayHistoAbs

See also

histo_2dimhisto_2dimhisto_2dimHisto2dimHisto2dim, scale_image_maxscale_image_maxscale_image_maxScaleImageMaxScaleImageMax

Module

Foundation