diff --git a/android/README.ANDROID b/android/README.ANDROID
index 334ce4a38..94429d86e 100644
--- a/android/README.ANDROID
+++ b/android/README.ANDROID
@@ -32,7 +32,7 @@ after some tweaks, but atm. only linux is supported.
 Dependencies list (may be incomplete):
 
     autoconf, automake, make, python, gradle, ant, imagemagick, cmake, 
-    vorbis-tools
+    vorbis-tools, pngquant
 
 Additionally some dependencies for optimize_data script:
 
diff --git a/android/generate_assets.sh b/android/generate_assets.sh
index 75b8811ca..6f640da35 100755
--- a/android/generate_assets.sh
+++ b/android/generate_assets.sh
@@ -14,8 +14,8 @@
 # value greater than 0.
 # The CONVERT_TO_JPG variable enables converting all images that are safe to 
 # convert and keeps other images untouched.
-# The script needs imagemagick and ogg utils installed to use DECREASE_QUALITY
-# feature
+# The script needs imagemagick, pngquant and ogg utils installed in order to 
+# use DECREASE_QUALITY feature
 
 ################################################################################
 
@@ -203,7 +203,7 @@ convert_image()
     fi
 
     convert $SCALE_CMD $QUALITY_CMD "$FILE" "tmp.$FILE_TYPE"
-
+    
     if [ -s "tmp.$FILE_TYPE" ]; then
         SIZE_OLD=`du -k "$FILE" | cut -f1`
         SIZE_NEW=`du -k "tmp.$FILE_TYPE" | cut -f1`
@@ -259,6 +259,19 @@ convert_sound()
     rm -f tmp.wav tmp.ogg
 }
 
+optimize_png()
+{
+    FILE="$1"
+    echo "Optimize file: $FILE"
+
+    if [ ! -f "$FILE" ]; then
+        echo "  File doesn't exist."
+        return
+    fi
+    
+    pngquant --force --skip-if-larger --output "$FILE" -- "$FILE"
+}
+
 convert_to_jpg()
 {
     FILE="$1"
@@ -347,7 +360,7 @@ convert_to_jpg()
 convert_to_jpg_extract_b3dz()
 {
     FILE="$1"
-    echo "Convert file: $FILE"
+    echo "Convert file to jpg: $FILE"
 
     if [ ! -f "$FILE" ]; then
         echo "  File doesn't exist."
@@ -368,7 +381,7 @@ convert_to_jpg_extract_b3dz()
 convert_to_jpg_update_b3d()
 {
     FILE="$1"
-    echo "Convert file: $FILE"
+    echo "Update b3d file: $FILE"
 
     if [ ! -f "$1" ]; then
         echo "  File doesn't exist."
@@ -448,7 +461,7 @@ convert_to_jpg_update_b3d()
 convert_to_jpg_update_spm()
 {
     FILE="$1"
-    echo "Convert file: $FILE"
+    echo "Update spm file: $FILE"
 
     if [ ! -f "$1" ]; then
         echo "  File doesn't exist."
@@ -520,7 +533,7 @@ convert_to_jpg_update_spm()
 convert_to_jpg_update_xml()
 {
     FILE="$1"
-    echo "Convert file: $FILE"
+    echo "Update xml file: $FILE"
 
     if [ ! -f "$FILE" ]; then
         echo "  File doesn't exist."
@@ -568,6 +581,10 @@ if [ $CONVERT_TO_JPG -gt 0 ]; then
     fi
 fi
 
+if [ $DECREASE_QUALITY -gt 0 ]; then
+    find assets/data -iname "*.png" | while read f; do optimize_png "$f" "png"; done
+fi
+
 
 # Copy data directory
 echo "Copy data directory"