+# converts an image $2 (format $1) to $4 (format $3)
+from __future__ import print_function
+import os, re, sys
+
+PY2 = sys.version_info[0] == 2
+
+# We may need some extra options only supported by recent convert versions
+re_version = re.compile(r'^Version:.*ImageMagick\s*(\d*)\.(\d*)\.(\d*).*$')
+# imagemagick 7
+command = 'magick'
+fout = os.popen('magick -version 2>&1')
+output = fout.readline()
+if fout.close() != None:
+ # older versions
+ # caution: windows has a convert.exe for converting file systems
+ command = 'convert'
+ fout = os.popen('convert -version 2>&1')
+ output = fout.readline()
+ fout.close()
+if not PY2:
+ output = output.decode()
+
+version = re_version.match(output)
+
+# Imagemagick by default
+im = False
+gm = False
+
+if version != None:
+ major = int(version.group(1))
+ minor = int(version.group(2))
+ patch = int(version.group(3))
+ version = hex(major * 65536 + minor * 256 + patch)
+ im = True
+else:
+ # Try GraphicsMagick
+ re_version = re.compile(r'^GraphicsMagick.*http:..www.GraphicsMagick.org.*$')
+ version = re_version.match(output)
+ if version != None:
+ gm = True
+
+if im or gm:
+ opts = "-depth 8"
+elif sys.platform == 'darwin':
+ command = 'lyxconvert'
+
+# If supported, add the -define option for pdf source formats
+if sys.argv[1] == 'pdf' and (version >= 0x060206 or gm):
+ opts = '-define pdf:use-cropbox=true ' + opts
+
+# If supported, add the -flatten option for ppm target formats (see bug 4749)
+if sys.argv[3] == 'ppm' and (im and version >= 0x060305 or gm):
+ opts = opts + ' -flatten'
+
+# print (command, sys.argv[2], sys.argv[4], file= sys.stdout)
+if (im or gm) and os.system(r'%s %s "%s" "%s"' % (command, opts, sys.argv[2], sys.argv[3] + ':' + sys.argv[4])) != 0:
+ print (sys.argv[0], 'ERROR', file= sys.stderr)
+ print ('Execution of "%s" failed.' % command, file= sys.stderr)
+ sys.exit(1)
+elif not im and not gm and sys.platform == 'darwin' and os.system(r'%s "%s" "%s"' % (command, sys.argv[2], sys.argv[4])) != 0:
+ print (sys.argv[0], 'ERROR', file= sys.stderr)
+ print ('Execution of "%s" failed.' % command, file= sys.stderr)