1Pamsummcol User Manual(0) Pamsummcol User Manual(0)
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6 pamsummcol - summarize (sum, average, etc) a Netpbm image by column
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10 pamsummcol { -sum | -mean | -min | -max } [imagefile]
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12 All options can be abbreviated to their shortest unique prefix. You
13 may use two hyphens instead of one. You may separate an option name
14 and its value with white space instead of an equals sign.
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18 This program is part of Netpbm(1).
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20 pamsummcol reads a Netpbm image (PNM or PAM) and performs a summary
21 function over all the rows in each column (sum, mean, etc.). It pro‐
22 duces an image of the same kind that the same width and depth as the
23 input, and one row high. Its sample values are the result of the sum‐
24 mary.
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26 pamsummcol performs the summary operation on each plane independently.
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28 pamsummcol performs the operation on the actual sample values, not on
29 the light intensities represented by them in the case that the image is
30 a PGM or PPM image.
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32 If you want to summarize by row instead of by column, run the input
33 through pamflip first (and if you want the output to be a single column
34 instead of a single row, use pamflip again).
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36 If you want to summarize over the entire image instead of over columns
37 separately, use pamsumm.
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39 pamsummcol performs the operation on the actual sample values, not on
40 the light intensities represented by them in the case that the image is
41 a PGM or PPM image or PAM equivalent. You can use pnmgamma to convert
42 such an image to one with samples proportional to light intensity, and
43 then use pamsummcol on the result.
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45 You can achieve the same thing as pamsummcol -mean with pamscale. Just
46 scale vertically to a single row, without scaling horizontally at all.
47 Use the pixel mixing method.
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52 You must specify exactly one of -sum, -mean, -min, or -max.
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56 -sum
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58 This option makes the summary function addition.
59 In each column and plane of the output row, the sample
60 value is the
61 sum of all the samples values in the same column and plane
62 of the input.
63 If a result is greater than the image maxval, it is clipped
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65 the maxval.
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68 -mean
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70 This option makes the summary function arithmetic mean.
71 In each column and plane of the output row, the sample
72 value is the
73 mean of all the samples values in the same column and plane
74 of the input.
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77 -min
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79 This option makes the summary function arithmetic minimum.
80 In each column and plane of the output row, the sample
81 value is the
82 minimum of all the samples values in the same column and
83 plane of
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87 -max
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89 This option makes the summary function arithmetic maximum.
90 In each column and plane of the output row, the sample
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92 the maximum of all the samples values in the same column
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94 plane of the input.
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100 pamsumm(1), pamscale(1), pamfunc(1), pamarith(1), pamscale(1), pam(1),
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104 pamsummcol was added to Netpbm in Release 10.21 (March 2004).
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108netpbm documentation 07 February 2004 Pamsummcol User Manual(0)