xil_histogram_create(3)

NAME

xil_histogram_create, xil_histogram_destroy − create or destroy histogram

SYNOPSIS

#include <xil/xil.h>

XilHistogram xil_histogram_create ( XilSystemState State,

unsigned int nbands,
unsigned int ∗nbins,
float ∗low_value,
float ∗high_value);

void xil_histogram_destroy ( XilHistogram histogram);

DESCRIPTION

These routines create and destroy histogram objects. Histograms are used to accumulate level information from images. XIL histograms can have arbitrary numbers of bands, but the number of bands must match the number of bands in the image that is to be histogrammed. A 3-banded histogram, for example, contains a cube of information that reflects pixel values in the three bands independently.

State is the XIL system state. nbands is the number of independent bands in the histogram. nbins is a pointer to an array that contains the number of bins for each band. These bins are used to hold information about gray or color levels.

low_value is a pointer to an array of floats that defines the value of the first bin for each band, and high_value is a pointer to an array of floats that defines the value of the last bin for each band. For each of the arrays nbins, low_value, and high_value, the number of elements in the array must match the number of bands in the image.

xil_histogram_destroy() destroys the specified histogram object.

ERRORS

For a complete list of XIL error messages by number, consult Appendix B of the XIL Programmer’s Guide.

EXAMPLES

Create a histogram structure appropriate for calculating the histogram of a 3-band XIL_BYTE image:

XilSystemState State;
XilHistogram histogram;
unsigned int nbins[3] = {32,32,32};
float low_value[3] = {0.0, 0.0, 0.0};
float high_value[3] = {255.0, 255.0, 255.0};
histogram = xil_histogram_create (State, 3, nbins, low_value, high_value);

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