[277] | 1 | #! /usr/bin/env python |
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| 2 | # -*- coding: ISO-8859-15 -*- |
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| 3 | # |
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| 4 | # pkpgcounter : a generic Page Description Language parser |
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| 5 | # |
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[303] | 6 | # (c) 2003, 2004, 2005, 2006 Jerome Alet <alet@librelogiciel.com> |
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[277] | 7 | # This program is free software; you can redistribute it and/or modify |
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| 8 | # it under the terms of the GNU General Public License as published by |
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| 9 | # the Free Software Foundation; either version 2 of the License, or |
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| 10 | # (at your option) any later version. |
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| 11 | # |
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| 12 | # This program is distributed in the hope that it will be useful, |
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| 13 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 15 | # GNU General Public License for more details. |
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| 16 | # |
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| 17 | # You should have received a copy of the GNU General Public License |
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| 18 | # along with this program; if not, write to the Free Software |
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| 19 | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
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| 20 | # |
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| 21 | # $Id$ |
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| 22 | # |
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| 23 | |
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[357] | 24 | """This modules implements the computation of ink coverage in different colorspaces.""" |
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| 25 | |
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[277] | 26 | import sys |
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| 27 | |
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| 28 | from PIL import Image |
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| 29 | |
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[363] | 30 | def getPercent(img, nbpix) : |
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| 31 | """Extracts the percents per color component from a picture. |
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| 32 | |
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| 33 | Faster without Psyco on my own machine. |
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| 34 | """ |
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| 35 | result = {} |
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| 36 | bands = img.split() |
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| 37 | for (i, bandname) in enumerate(img.getbands()) : |
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| 38 | result[bandname] = 100.0 * (reduce(lambda current, next: current + (next[1] * next[0]), enumerate(bands[i].histogram()), 0) / 255.0) / nbpix |
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| 39 | return result |
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| 40 | |
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[280] | 41 | def getPercentCMYK(img, nbpix) : |
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| 42 | """Extracts the percents of Cyan, Magenta, Yellow, and Black from a picture. |
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| 43 | |
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| 44 | PIL doesn't produce useable CMYK for our algorithm, so we use the algorithm from PrintBill. |
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| 45 | Psyco speeds this function up by around 2.5 times on my computer. |
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| 46 | """ |
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| 47 | if img.mode != "RGB" : |
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| 48 | img = img.convert("RGB") |
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[287] | 49 | data = img.getdata() |
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[280] | 50 | cyan = magenta = yellow = black = 0 |
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[287] | 51 | for (r, g, b) in data : |
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[280] | 52 | if r == g == b : |
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| 53 | black += 255 - r |
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| 54 | else : |
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| 55 | cyan += 255 - r |
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| 56 | magenta += 255 - g |
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| 57 | yellow += 255 - b |
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| 58 | return { "C" : 100.0 * (cyan / 255.0) / nbpix, |
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| 59 | "M" : 100.0 * (magenta / 255.0) / nbpix, |
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| 60 | "Y" : 100.0 * (yellow / 255.0) / nbpix, |
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| 61 | "K" : 100.0 * (black / 255.0) / nbpix, |
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| 62 | } |
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| 63 | |
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[363] | 64 | def getPercentBW(img, nbpix) : |
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[280] | 65 | """Extracts the percents of Black from a picture, once converted to gray levels.""" |
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[279] | 66 | if img.mode != "L" : |
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| 67 | img = img.convert("L") |
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[363] | 68 | return { "B" : 100.0 - getPercent(img, nbpix)["L"] } |
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[279] | 69 | |
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[280] | 70 | def getPercentRGB(img, nbpix) : |
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| 71 | """Extracts the percents of Red, Green, Blue from a picture, once converted to RGB.""" |
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| 72 | if img.mode != "RGB" : |
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| 73 | img = img.convert("RGB") |
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| 74 | return getPercent(img, nbpix) |
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| 75 | |
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| 76 | def getPercentCMY(img, nbpix) : |
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| 77 | """Extracts the percents of Cyan, Magenta, and Yellow from a picture once converted to RGB.""" |
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| 78 | result = getPercentRGB(img, nbpix) |
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| 79 | return { "C" : 100.0 - result["R"], |
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| 80 | "M" : 100.0 - result["G"], |
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| 81 | "Y" : 100.0 - result["B"], |
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| 82 | } |
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| 83 | |
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[363] | 84 | def getInkCoverage(fname, colorspace) : |
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| 85 | """Returns a list of dictionnaries containing for each page, |
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| 86 | for each color component, the percent of ink coverage on |
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| 87 | that particular page. |
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| 88 | """ |
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[281] | 89 | result = [] |
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[363] | 90 | colorspace = colorspace.upper() |
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| 91 | computation = globals()["getPercent%s" % colorspace] |
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| 92 | if colorspace == "CMYK" : # faster with psyco on my machine |
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| 93 | try : |
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| 94 | import psyco |
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| 95 | except ImportError : |
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| 96 | pass |
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| 97 | else : |
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| 98 | psyco.bind(computation) |
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| 99 | |
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[281] | 100 | index = 0 |
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[279] | 101 | image = Image.open(fname) |
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[281] | 102 | try : |
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| 103 | while 1 : |
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| 104 | nbpixels = image.size[0] * image.size[1] |
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[376] | 105 | result.append(computation(image, nbpixels)) |
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[281] | 106 | index += 1 |
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| 107 | image.seek(index) |
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| 108 | except EOFError : |
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| 109 | pass |
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[376] | 110 | return (colorspace, result) |
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[277] | 111 | |
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| 112 | if __name__ == "__main__" : |
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[281] | 113 | # NB : length of result gives number of pages ! |
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[363] | 114 | print getInkCoverage(sys.argv[1], "CMYK") |
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