Initial gimp_stack.lua from wpferguson

Received from wpferguson 2019-11-24 via
darktable-org#196 (comment)

Author: agittins

contrib/gimp_stack.lua

@@ -0,0 +1,140 @@
+--[[
+
+    gimp_stack.lua - export multiple images and open as layers in gimp
+
+    Copyright (C) 2016 Bill Ferguson <[email protected]>.
+
+    Portions are lifted from hugin.lua and thus are 
+
+    Copyright (c) 2014  Wolfgang Goetz
+    Copyright (c) 2015  Christian Kanzian
+    Copyright (c) 2015  Tobias Jakobs
+
+
+    This program 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.
+
+    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+]]
+--[[
+    gimp_stack - export multiple images and open as layers with gimp for editing
+
+    This script provides another storage (export target) for darktable.  Selected
+    images are exported in the specified format to temporary storage.  The images are 
+    combined into a single file. Gimp is launched and opens the merged file.  A dialog 
+    prompts to import the image as layers. After editing, the image is imported back into
+    the current collection, using the path of the first image selected, as stack.tif.  
+    The image is then imported into the database.  The exported files that made up the 
+    stacked image are deleted from temporary storage to avoid cluttering up the system. 
+    
+
+    ADDITIONAL SOFTWARE NEEDED FOR THIS SCRIPT
+    * gimp - http://www.gimp.org
+    * imagemagick - http://www.imagemagick.org
+
+    USAGE
+    * require this script from your main lua file
+    * select an images to stack and edit with gimp
+    * in the export dialog select "Edit as layers with gimp" and select the format and bit depth for the
+      exported image
+    * Press "export"
+    * Import the image as layers when gimp starts
+    * Edit the image with gimp then save the changes with File->Overwrite....
+    * Exit gimp
+    * The edited image will be imported and grouped with the original collection
+
+    CAVEATS
+    * Developed and tested on Ubuntu 14.04 LTS with darktable 2.0.3 and gimp 2.9.3 (development version with
+      > 8 bit color)
+    * There is no provision for dealing with the xcf files generated by gimp, since darktable doesn't deal with 
+      them.  You may want to save the xcf file if you intend on doing further edits to the image or need to save 
+      the layers used.  Where you save them is up to you.
+
+    BUGS, COMMENTS, SUGGESTIONS
+    * Send to Bill Ferguson, [email protected]
+]]
+
+local dt = require "darktable"
+local dtutils = require "contrib/dtutils"
+local gettext = dt.gettext
+
+dt.configuration.check_version(...,{3,0,0})
+
+-- Tell gettext where to find the .mo file translating messages for a particular domain
+gettext.bindtextdomain("gimp_stack",dt.configuration.config_dir.."/lua/")
+
+-- Thanks to http://lua-users.org/wiki/SplitJoin for the split and split_path functions
+local function _(msgid)
+    return gettext.dgettext("gimp_stack", msgid)
+end
+
+local function show_status(storage, image, format, filename,
+  number, total, high_quality, extra_data)
+  dt.print(string.format(_("Exporting to gimp %i/%i"), number, total))
+end
+
+local function gimp_stack_edit(storage, image_table, extra_data) --finalize
+  if not dtutils.checkIfBinExists("gimp") then
+    dt.print_error(_("gimp not found"))
+    return
+  end
+
+  if not dtutils.checkIfBinExists("convert") then
+    dt.print_error(_("convert not found"))
+    return
+  end
+
+  -- list of exported images 
+  local img_list
+
+   -- reset and create image list
+  img_list = ""
+
+  for _,exp_img in pairs(image_table) do
+    img_list = img_list ..exp_img.. " "
+  end
+  dt.print_error(img_list)
+
+  local tmp_stack_image = dt.configuration.tmp_dir.."/stack.tif"
+
+  dt.print(_("Stacking images..."))
+
+  os.execute("convert "..img_list.." "..tmp_stack_image)
+  os.execute("rm "..img_list)
+
+  dt.print(_("Launching gimp..."))
+
+  local gimpStartCommand
+  gimpStartCommand = "gimp "..tmp_stack_image
+  
+  dt.print_error(gimpStartCommand)
+
+  coroutine.yield("RUN_COMMAND", gimpStartCommand)
+
+  -- for each of the exported images
+  -- find the matching original image
+  -- then move the exported image into the directory with the original  
+  -- then import the image into the database which will group it with the original
+  -- and then copy over any tags other than darktable tags
+
+  local collection_path = dt.gui.action_images[1].path
+  local final_stack_image = collection_path.."/stack.tif"
+  os.execute("mv "..tmp_stack_image.." "..final_stack_image)
+  local myimage = dt.database.import(final_stack_image)
+  
+end
+
+-- Register
+dt.register_storage("module_gimp_stack", _("Edit as layers with gimp"), show_status, gimp_stack_edit)
+
+--
+
+