Merge pull request #92 from khampf/passport-guide

ISO 19794-5/ICAO 9303 clipping guide as contrib/passport_guide.lua

contrib/passport_guide.lua

@@ -0,0 +1,94 @@
+--[[
+  Passport cropping guide for darktable
+
+  copyright (c) 2017  Kåre Hampf
+  
+  darktable is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  darktable is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with darktable.  If not, see <http://www.gnu.org/licenses/>.
+]]
+
+--[[
+PASSPORT CROPPING GUIDE
+guides for cropping passport photos based on documents from the Finnish police
+(https://www.poliisi.fi/instancedata/prime_product_julkaisu/intermin/embeds/poliisiwwwstructure/38462_Passikuvaohje_EN.pdf) describing passport photo dimensions of 47x36 mm and 500x653 px for digital biometric data stored in passports. They use ISO 19794-5 standard based on ICAO 9303 regulations which should also be compliant for all of Europe.
+
+INSTALLATION
+* copy this file in $CONFIGDIR/lua/ where CONFIGDIR is your darktable configuration directory
+* add the following line in the file $CONFIGDIR/luarc
+  require "passport_guide"
+* (optional) add the line:
+  "plugins/darkroom/clipping/extra_aspect_ratios/passport 36x47mm=47:36"
+  to $CONFIGDIR/darktablerc
+
+USAGE
+* when using the cropping tool, select "passport" as guide and if you added the line in yout rc
+  select "passport 36x47mm" as aspect
+]]
+
+local dt = require "darktable"
+local gettext = dt.gettext
+
+dt.configuration.check_version(...,{2,0,0},{3,0,0},{4,0,0},{5,0,0})
+
+-- Tell gettext where to find the .mo file translating messages for a particular domain
+gettext.bindtextdomain("passport_guide",dt.configuration.config_dir.."/lua/locale/")
+
+local function _(msgid)
+  return gettext.dgettext("passport_guide", msgid)
+end
+
+dt.guides.register_guide("passport",
+-- draw
+function(cairo, x, y, width, height, zoom_scale)
+  local _width, _height
+
+  -- get the max 36x47 rectangle
+  local aspect_ratio = 47 / 36
+  if width * aspect_ratio > height then
+    _width = height / aspect_ratio
+    _height = height
+  else
+    _width = width
+    _height = width * aspect_ratio
+  end
+
+  cairo:save()
+
+  cairo:translate(x + (width - _width) / 2, y + (height - _height) / 2)
+  cairo:scale(_width / 36, _height / 47)
+
+  -- the outer rectangle
+  cairo:rectangle( 0, 0, 36, 47)
+
+  -- vertical bars
+  cairo:draw_line(16.5, 8, 16.5, 36)
+  cairo:draw_line(19.5, 8, 19.5, 36)
+
+  -- long horisontal bars
+  cairo:draw_line(6, 4, 30, 4)
+  cairo:draw_line(6, 40, 30, 40)
+
+  -- short horisontal bars
+  cairo:draw_line(9, 6, 27, 6)
+  cairo:draw_line(9, 38, 27, 38)
+
+  cairo:restore()
+end,
+-- gui
+function()
+  return dt.new_widget("label"){label = _("ISO 19794-5/ICAO 9309 passport"), halign = "start"}
+end
+)
+
+-- kate: tab-indents: off; indent-width 2; replace-tabs on; remove-trailing-space on; hl Lua;
+-- vim: shiftwidth=2 expandtab tabstop=2 cindent syntax=lua