[gimp-data-extras] plug-ins: move benchmark-foreground-extract from GIMP repo.

[Jehan <jehanp src gnome org>]

commit 57710ed02f4f6e1def7484c49387324e52a7ffd6
Author: Jehan <jehan girinstud io>
Date:   Mon Apr 19 18:07:12 2021 +0200

    plug-ins: move benchmark-foreground-extract from GIMP repo.
    
    We did port it to the new API but we are doubting it is useful at all.
    It might have been, historically, when foreground extract algorithm was
    first introduced, but probably not anymore, even more as the algorithm
    is now implemented mostly on GEGL side anyway. So if any benchmark were
    to be done, it should probably be added as GEGL tests.
    
    Still we move it to the gimp-data-extras repository for being able to
    easily bring it back in case we missed some use.

 plug-ins/python3/Makefile.am                     |  10 +
 plug-ins/python3/benchmark-foreground-extract.py | 250 +++++++++++++++++++++++
 2 files changed, 260 insertions(+)
---
diff --git a/plug-ins/python3/Makefile.am b/plug-ins/python3/Makefile.am
index 408d48d..b18f2ba 100644
--- a/plug-ins/python3/Makefile.am
+++ b/plug-ins/python3/Makefile.am
@@ -2,10 +2,20 @@
 
 if ENABLE_GIMP3
 
+# The benchmark_foreground_extract plug-in used to be only installed for
+# unstable GIMP builds. We moved it to gimp-data-extras in case someone
+# decide it was actually still useful, but won't install it, at least
+# for now.
+
+#benchmark_foreground_extractdir = $(gimpplugindir)/plug-ins/benchmark-foreground-extract
+#benchmark_foreground_extract_SCRIPTS = benchmark-foreground-extract.py
+
 py_slicedir = $(GIMP3_PLUG_INS_DIR)/py-slice
 py_slice_SCRIPTS = py-slice.py
 
 EXTRA_DIST = \
         py-slice.py
 
+#EXTRA_DIST += benchmark-foreground-extract.py
+
 endif
diff --git a/plug-ins/python3/benchmark-foreground-extract.py 
b/plug-ins/python3/benchmark-foreground-extract.py
new file mode 100755
index 0000000..90806a5
--- /dev/null
+++ b/plug-ins/python3/benchmark-foreground-extract.py
@@ -0,0 +1,250 @@
+#!/usr/bin/env python3
+
+#   Foreground Extraction Benchmark
+#   Copyright 2005  Sven Neumann <sven gimp org>
+#
+"""
+  This is a from-scratch implementation of the benchmark proposed in
+  "GrabCut": interactive foreground extraction using iterated graph
+  cuts published in the Proceedings of the 2004 SIGGRAPH Conference.
+
+  No guarantee is made that this benchmark produces the same results
+  as the cited benchmark but the goal is that it does. So if you find
+  any bugs or inaccuracies in this code, please let us know.
+
+  The benchmark has been adapted work with the MATTING algorithm,
+  which is (currently) the only
+  implementation of gimp_drawable_foreground_extract(). If other
+  implementations are being added, this benchmark should be changed
+  accordingly.
+
+  You will need a set of test images to run this benchmark, preferably
+  the original set of 50 images. Some of these images are from the
+  Berkeley Segmentation Dataset
+  http://www.cs.berkeley.edu/projects/vision/grouping/segbench/ .
+  See http://www.siox.org/details.html to download trimaps.
+  See https://web.archive.org/web/20050209123253/http://research.microsoft.com/vision/cambridge/segmentation/
+  and download the "Labelling - Lasso" file.
+"""
+#   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 <https://www.gnu.org/licenses/>.
+
+import os, re, struct, sys, time
+
+import gi
+gi.require_version('Gimp', '3.0')
+from gi.repository import Gimp
+from gi.repository import GObject
+from gi.repository import GLib
+from gi.repository import Gio
+
+
+def benchmark (procedure, args, data):
+    if args.length() != 3:
+        error = 'Wrong parameters given'
+        return procedure.new_return_values(Gimp.PDBStatusType.CALLING_ERROR,
+                                           GLib.Error(error))
+    run_mode = args.index(0)
+    folder = args.index(1)
+    save_output = args.index(2)
+
+    folder = os.path.abspath(os.path.expanduser(folder))
+    if not os.path.exists(folder):
+        error = "Folder '" + folder + "' doesn't exist.\n"
+        return procedure.new_return_values(Gimp.PDBStatusType.CALLING_ERROR,
+                                           GLib.Error(error))
+
+    total_unclassified = 0
+    total_misclassified = 0
+    total_time = 0.0
+
+    images = os.path.join(folder, "images")
+    for name in os.listdir(images):
+
+        try:
+            image_display.delete()
+            mask_display.delete()
+        except NameError:
+            pass
+
+        image_name = os.path.join (images, name)
+
+        # Remove suffix, assuming it has three characters
+        name = re.sub(r'\....$', '', name)
+
+        mask_name = os.path.join(folder, "cm_bmp", name + '.png')
+        truth_name = os.path.join(folder, "truth", name + '.bmp')
+
+        image = Gimp.file_load(run_mode, Gio.file_new_for_path(image_name))
+        image_layer = image.get_active_layer()
+
+        mask = Gimp.file_load(run_mode, Gio.file_new_for_path(mask_name))
+        convert_grayscale(mask)
+        mask_layer = mask.get_active_layer()
+
+        truth = Gimp.file_load(run_mode, Gio.file_new_for_path(truth_name))
+        convert_grayscale(truth)
+        truth_layer = truth.get_active_layer()
+
+        unclassified = unclassified_pixels(mask_layer, truth_layer)
+
+        sys.stderr.write(os.path.basename (image_name))
+
+        start = time.time()
+        image_layer.foreground_extract(Gimp.ForegroundExtractMode.MATTING, mask_layer)
+        end = time.time()
+
+        sys.stderr.write(" ")
+
+        # This line was in the gimp 2 implementation, and probably isn't needed anymore.
+        #  mask_layer.flush ()
+
+        # Ignore errors when creating image displays;
+        # allows us to be used without a display.
+        try:
+            image_display = Gimp.Display.new(image)
+            mask_display = Gimp.Display.new(mask)
+
+            Gimp.displays_flush()
+            time.sleep(1.0)
+        except:
+            pass
+
+        image.delete()
+
+        misclassified = misclassified_pixels (mask_layer, truth_layer)
+
+        sys.stderr.write("%d %d %.2f%% %.3fs\n" %
+                         (unclassified, misclassified,
+                          (misclassified * 100.0 / unclassified),
+                          end - start))
+
+        total_unclassified += unclassified
+        total_misclassified += misclassified
+        total_time += end - start
+
+        truth.delete()
+
+        if save_output:
+            filename = os.path.join(folder, "output", name + '.png')
+            Gimp.file_save(Gimp.RunMode.NONINTERACTIVE, mask, mask_layer, Gio.file_new_for_path(filename))
+
+        mask.delete()
+
+    # for loop ends
+
+    try:
+        image_display.delete()
+        mask_display.delete()
+    except NameError:
+        pass
+
+    sys.stderr.write("Total: %d %d %.2f%% %.3fs\n" %
+                     (total_unclassified, total_misclassified,
+                       (total_misclassified * 100.0 / total_unclassified),
+                       total_time))
+
+    return procedure.new_return_values(Gimp.PDBStatusType.SUCCESS, GLib.Error())
+
+
+def convert_grayscale(image):
+    if not image.get_effective_color_profile().is_gray():
+        image.convert_grayscale()
+
+
+def unclassified_pixels(mask, truth):
+    (result, mean, std_dev, median, pixels,
+     count, percentile) = mask.histogram(Gimp.HistogramChannel.VALUE, 2/256.0, 254/256.0)
+
+    return count
+
+
+def misclassified_pixels(mask, truth):
+    image = truth.get_image()
+
+    copy = Gimp.Layer.new_from_drawable(mask, image)
+    copy.set_name("Difference")
+    copy.set_mode(Gimp.LayerMode.DIFFERENCE_LEGACY)
+
+    image.insert_layer(copy, None, -1)
+
+    # The assumption made here is that the output of
+    # foreground_extract is a strict black and white mask. The truth
+    # however may contain unclassified pixels. These are considered
+    # unknown, a strict segmentation isn't possible here.
+    #
+    # The result of using the Difference mode as done here is that
+    # pure black pixels in the result can be considered correct.
+    # White pixels are wrong. Gray values were unknown in the truth
+    # and thus are not counted as wrong.
+
+    flat_image = image.flatten()
+    (result, mean, std_dev, median, pixels,
+     count, percentile) = flat_image.histogram(Gimp.HistogramChannel.VALUE, 254/256.0, 1.0)
+
+    return count
+
+
+PROCNAME = "python-fu-benchmark-foreground-extract"
+
+class BenchmarkForegroundExtract(Gimp.PlugIn):
+
+    ## Parameters ##
+    __gproperties__ = {
+        "run-mode": (Gimp.RunMode,
+                     "Run mode",
+                     "The run mode",
+                     Gimp.RunMode.NONINTERACTIVE,
+                     GObject.ParamFlags.READWRITE),
+        "image_folder": (str,
+                        "Image Folder",
+                        "Image Folder",
+                        "~/segmentation/msbench/imagedata",
+                        GObject.ParamFlags.READWRITE),
+        "save_output": (bool,
+                        "Save output images",
+                        "Save output images",
+                        False,
+                        GObject.ParamFlags.READWRITE)
+    }
+
+    ## GimpPlugIn virtual methods ##
+    def do_query_procedures(self):
+        self.set_translation_domain("gimp30-python",
+                                    Gio.file_new_for_path(Gimp.locale_directory()))
+        return [PROCNAME]
+
+    def do_create_procedure(self, name):
+        procedure = None
+        if name == PROCNAME:
+            procedure = Gimp.Procedure.new(self, name,
+                                           Gimp.PDBProcType.PLUGIN,
+                                           benchmark, None)
+            procedure.set_documentation(
+                "Benchmark and regression test for Foreground Extraction",
+                globals()["__doc__"],  # This includes the docstring, on the top of the file
+                name)
+            procedure.set_menu_label("Foreground Extraction")
+            procedure.set_attribution("Sven Neumann",
+                                      "Sven Neumann",
+                                      "2005")
+            procedure.add_menu_path("<Image>/Filters/Extensions/Benchmark")
+
+            procedure.add_argument_from_property(self, "run-mode")
+            procedure.add_argument_from_property(self, "image_folder")
+            procedure.add_argument_from_property(self, "save_output")
+
+        return procedure
+
+
+Gimp.main(BenchmarkForegroundExtract.__gtype__, sys.argv)