From fc9fec465faba49c2582993403a7f1d706d687ad Mon Sep 17 00:00:00 2001
From: DRC <dcommander@users.sourceforge.net>
Date: Sat, 19 Jan 2013 06:43:27 +0000
Subject: [PATCH] ImageIO.read() returns null if the input image type is not
 supported (which occurs when trying to read a PPM file), so output a friendly
 error instead of letting the next line throw a null pointer exception.

---
 java/TJExample.java | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/java/TJExample.java b/java/TJExample.java
index e7268928..14809410 100644
--- a/java/TJExample.java
+++ b/java/TJExample.java
@@ -273,6 +273,8 @@ public class TJExample implements TJCustomFilter {
       }
       else {
         img = ImageIO.read(file);
+        if (img == null)
+          throw new Exception("Input image type not supported.");
         width = img.getWidth();
         height = img.getHeight();
         if(outSubsamp < 0) {