diff --git a/libs/jpg_bin.py b/libs/jpg_bin.py
index a6fbd23..70fe73b 100644
--- a/libs/jpg_bin.py
+++ b/libs/jpg_bin.py
@@ -144,6 +144,7 @@ class JpgBin:
   def markerAppData(self, marker_hex):
     self.__addPrevMarkerData(marker_hex, "APP ", False)
     rec_len = self.__calcSeekBytes()
+    logging.info("length=={}".format(str(rec_len)))
 
   #
   def markerComment(self, marker_hex):
@@ -156,19 +157,23 @@ class JpgBin:
   #
   def markerSOS(self, marker_hex):
     self.__addPrevMarkerData(marker_hex, "SOS ")
+    self.data_idx += 2
+
 
   #
   def markerRST(self, marker_hex):
     self.__addPrevMarkerData(marker_hex, "RST ")
+    self.data_idx += 2
 
   #
   def markerDQT(self, marker_hex):
-    rec_len = self.__calcSeekBytes()
     self.__addPrevMarkerData(marker_hex, "DQT ")
+    rec_len = self.__calcSeekBytes()
 
   #
   def markerDRI(self, marker_hex):
     self.__addPrevMarkerData(marker_hex, "DRI ")
+    self.data_idx += 4
 
   #
   def markerSOF0(self, marker_hex):
@@ -188,6 +193,7 @@ class JpgBin:
   def markerEOI(self, marker_hex):
     self.__addPrevMarkerData(marker_hex, "EOI ")
     self.__addPrevMarkerData(marker_hex, "JUST A DUMMY VALUE")
+    self.data_idx += 2
 
 
   # private helper function
@@ -204,7 +210,6 @@ class JpgBin:
     self.prev_mhex = mhex
     self.prev_mstr = mstr
     self.prev_fpos = cur_fpos
-    self.data_idx += 2
     self.prev_imgData = imgData
 
   #
diff --git a/libs/jpg_bin_w.py b/libs/jpg_bin_w.py
index 731214a..77686be 100644
--- a/libs/jpg_bin_w.py
+++ b/libs/jpg_bin_w.py
@@ -3,9 +3,9 @@
 #
 class JpgBinWrite:
 
-  soi_marker     = 0xffd8
-  eof_marker     = 0xffd9
-  picseal_marker = 0xffe0
+  soi_marker     = b'\xff\xd8'
+  eof_marker     = b'\xff\xd9'
+  picseal_marker = b'\xff\xe0'
 
   #
   def __init__(self, jpg_in, jpg_out):
@@ -49,6 +49,7 @@ class JpgBinWrite:
       self.fhr.seek(marker.fpos)
       data = self.fhr.read(marker.len)
       self.fhw.write(data)
+      self.fhw.flush()
     
   #
   # array of the marker information
@@ -62,6 +63,7 @@ class JpgBinWrite:
 
       data = self.fhr.read(marker.len)
       self.fhw.write(data)
+      self.fhw.flush()
 
   #
   def __writeJpgHeader(self):
diff --git a/picseal.py b/picseal.py
index 1c1c11f..2bdab4c 100644
--- a/picseal.py
+++ b/picseal.py
@@ -20,14 +20,14 @@ def main():
 # create new pub keys, sign hash
 # export signature & public key to a new image file
 def processImage(image_fn):
-  jpg = JpgProc()
-  jpg.process(image_fn)
-  jpg.hash()
+  jpg_proc = JpgProc()
+  jpg_proc.process(image_fn)
+  jpg_proc.hash()
   if (write_picseal):
     print("Writing PicSeal JPG files...")
-    jpg.writePicSealJpg()
+    jpg_proc.writePicSealJpg()
 
-  printImageInfo(jpg)
+  printImageInfo(jpg_proc.jpg)
 
 #
 def printImageInfo(jpg_bin):