Merge pull request #5489

905711f contrib: improve optimize-pngs.py (Wladimir J. van der Laan)
42f6a0c [Qt] optimize PNG files (Jonas Schnelli)

contrib/devtools/optimize-pngs.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+
+import os
+import sys
+import subprocess
+import hashlib
+from PIL import Image
+
+def file_hash(filename):
+    '''Return hash of raw file contents'''
+    with open(filename, 'rb') as f:
+        return hashlib.sha256(f.read()).hexdigest()
+
+def content_hash(filename):
+    '''Return hash of RGBA contents of image'''
+    i = Image.open(filename)
+    i = i.convert('RGBA')
+    data = i.tostring()
+    return hashlib.sha256(data).hexdigest()
+
+#optimize png, remove various color profiles, remove ancillary chunks (alla) and text chunks (text)
+#pngcrush -brute -ow -rem gAMA -rem cHRM -rem iCCP -rem sRGB -rem alla -rem text
+
+pngcrush = 'pngcrush'
+git = 'git'
+folders = ["src/qt/res/movies", "src/qt/res/icons", "src/qt/res/images"]
+basePath = subprocess.check_output([git, 'rev-parse', '--show-toplevel']).rstrip('\n')
+totalSaveBytes = 0
+
+outputArray = []
+for folder in folders:
+    absFolder=os.path.join(basePath, folder)
+    for file in os.listdir(absFolder):
+        extension = os.path.splitext(file)[1]
+        if extension.lower() == '.png':
+            print("optimizing "+file+"..."),
+            file_path = os.path.join(absFolder, file)
+            fileMetaMap = {'file' : file, 'osize': os.path.getsize(file_path), 'sha256Old' : file_hash(file_path)};
+            fileMetaMap['contentHashPre'] = content_hash(file_path)
+        
+            pngCrushOutput = ""
+            try:
+                pngCrushOutput = subprocess.check_output(
+                        [pngcrush, "-brute", "-ow", "-rem", "gAMA", "-rem", "cHRM", "-rem", "iCCP", "-rem", "sRGB", "-rem", "alla", "-rem", "text", file_path],
+                        stderr=subprocess.STDOUT).rstrip('\n')
+            except:
+                print "pngcrush is not installed, aborting..."
+                sys.exit(0)
+        
+            #verify
+            if "Not a PNG file" in subprocess.check_output([pngcrush, "-n", "-v", file_path], stderr=subprocess.STDOUT):
+                print "PNG file "+file+" is corrupted after crushing, check out pngcursh version"
+                sys.exit(1)
+            
+            fileMetaMap['sha256New'] = file_hash(file_path)
+            fileMetaMap['contentHashPost'] = content_hash(file_path)
+
+            if fileMetaMap['contentHashPre'] != fileMetaMap['contentHashPost']:
+                print "Image contents of PNG file "+file+" before and after crushing don't match"
+                sys.exit(1)
+
+            fileMetaMap['psize'] = os.path.getsize(file_path)
+            outputArray.append(fileMetaMap)
+            print("done\n"),
+
+print "summary:\n+++++++++++++++++"
+for fileDict in outputArray:
+    oldHash = fileDict['sha256Old']
+    newHash = fileDict['sha256New']
+    totalSaveBytes += fileDict['osize'] - fileDict['psize']
+    print fileDict['file']+"\n  size diff from: "+str(fileDict['osize'])+" to: "+str(fileDict['psize'])+"\n  old sha256: "+oldHash+"\n  new sha256: "+newHash+"\n"
+    
+print "completed. Total reduction: "+str(totalSaveBytes)+" bytes"