HISDUMP

Description

HISDUMP generates an image histogram report for one or more import channels. The report lists the pixel values and their counts.

Parameters

Name	Type	Length	Value range
Input: Layer(s): Input raster channel(s) *	Raster port	1 - 1024
Mask	Integer	0 - 4
Port Settings: Resample Mode: Port Settings: Resample mode	Raster port	1 - 1024	Nearest \| Bilinear \| Cubic Default: Nearest
Histogram Window	Float	0 - 4
Histogram Dump Format	String	0 - 1	RAW \| RANGE \| HITRANGE \| CENTER \| HITCENTER Default: HITCENTER
Report	String	0 - 192	See parameter description

* Required parameter

Parameter descriptions

Input: Layer(s): Input raster channel(s)

The image channels from which to extract histogram data.

Mask

The window or bitmap that defines the area to process within the input raster.

If no value is specified, the entire channel is processed.

Port Settings: Resample Mode: Port Settings: Resample mode

The method to use for image resampling.

Supported methods include:

Nearest: Nearest-neighbor interpolation identifies the gray level of the pixel closest to the specified input coordinates and assigns that value to the output coordinates. This is the default value.
Bilinear: Bilinear interpolation determines the gray level from the weighted average of the four closest pixels to the specified input coordinates and assigns that value to the output coordinates.
Cubic: Cubic convolution determines the gray level from the weighted average of the 16 closest pixels to the specified input coordinates and assigns that value to the output coordinates.

Histogram Window

The minimum and maximum gray-level values to collect for the histogram.

If no value is specified for this parameter, the default depends on the type of the input channel:

8-bit: the range is -0 to 255
16-bit signed or 32-bit real: -32768 to 32767
16-bit unsigned: 0 to 65535

Note: This parameter gives the low bound of the first bin and the upper bound of the highest bin; it does not specify the center of the first and last bins. Pixels that do not fall within the binning range are ignored and not included in the histogram.

Histogram Dump Format

The format of the output histogram report.

Available options are:

RAW: generates one line per bin, with one column per sampled image channel. The column contains integer counts of pixels that fall into this bin's category from the specified channel.
RANGE: generates one line per bin, with the first two columns containing the bin minimum and the second column containing the bin maximum.
HITRANGE: same as RANGE, but output lines are generated only for bins having at least one non-zero count.
CENTER: generates one line per bin, with the first column containing the center gray-level value for the bin.
HITCENTER: same as CENTER, but output lines are generated only for bins having at least one non-zero value. This is the default value.

Report

Specifies where to direct the generated report.

Available options are:

LOG: generates a report on the terminal (default)
<modulename.RPT>: appends a report to the module's RPT file
DISK: generates a report on file "IMPRPT.LST"

Details

HISDUMP computes a histogram of one or more image channels, and exports (dumps) the result to a report file you specify. The format of the report is intended for ease of reading for statistical analysis by other functions, rather than be easily human-readable.

Note: You can generate a histogram report in a more easy-to-read format by running the HIS algorithm. CATALYST Professional Focus also has an interactive histogram tool with which you can generate a text data file or PostScript plots.

The source image channels are read from an input image file. If you want to restrict the set of pixels sampled, you can specify a window or graphic plane using the Mask (MASK) parameter.

When computing a histogram, HISDUMP establishes a histogram table with each entry in the table called a bin. A particular bin will contain a count of all sampled pixels that fall within the bin minimum (inclusive) and maximum (not included) gray-level values. You can control the overall binning range by specifying a value for the Histogram Window (HISW) parameter.

With the Histogram Dump Format (HISFORM) parameter, you can control the format of the generated histogram report. The simplest form is a "RAW" report, which generates one report line per histogram table bin, with the line containing the counts for each input channel sampled. The RANGE and CENTER report types add a column at the beginning of each line that contains the gray-level range for the bin, or the central gray-level value for the bin. The HITRANGE and HITCENTER report types are similar, but contain only lines for bins that have at least one nonzero count.

Environments	PYTHON :: EASI :: MODELER
Batch Mode	Yes
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HISDUMP

Image histogram export

Description

Parameters

Parameter descriptions

Details