.TH "pfsstat" 1 .SH NAME pfsstat \- Show frame / image statistics .SH SYNOPSIS .B pfsstat .SH DESCRIPTION This command will show a short text statistic on each image in the pfs stream. In the statistics you can find: .TP \fBFile\fR - name of the input file .TP \fBWidth, Height\fR - image dimensions .TP \fBMinimum\fR - minimum luminance of an image(*), given in linear units (relative luminance in cd/m^2) and logarithmic units .TP \fBMaximum\fR - maximum luminance of an image(*) .TP \fBAverage\fR - average luminance of an image(*) .TP \fBMean\fR - mean luminance of an image(*) .PP (*) Before min, max, average, median and dynamic range is computed, the following processing is performed on an image: 1) negative and zero values are replaced with the smallest positive value (to compute logarithms); 2) the image is low-pass filtered. The low-pass filtering removes few very dark or very bright pixels that can significantly influence estimation of the dynamic range. The percentile, instead of a low-pass filter, is sometimes used for the same purpose. However, a low-pass filter is preferred to the percentile in pfstools since, taking into account the processing that is happening in the human visual system, low-frequency band filter is more plausible. .PP Note: This command requires GNU Octave. .SH EXAMPLES .TP pfsin memorial.hdr | pfsstat .PP Show statistics for the memorial image. .SH BUGS Please report bugs and comments to Rafal Mantiuk .