From 6025b6016517c6d898d8957d1d7e03ba71431912 Mon Sep 17 00:00:00 2001
From: tknall <tknall@7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c>
Date: Fri, 1 Dec 2006 12:20:24 +0000
Subject: Initial import of release 2.2.

git-svn-id: https://joinup.ec.europa.eu/svn/pdf-as/trunk@4 7b5415b0-85f9-ee4d-85bd-d5d0c3b42d1c
---
 .../pdfbox/pdmodel/graphics/predictor/Average.java | 81 ++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 src/main/java/org/pdfbox/pdmodel/graphics/predictor/Average.java

(limited to 'src/main/java/org/pdfbox/pdmodel/graphics/predictor/Average.java')

diff --git a/src/main/java/org/pdfbox/pdmodel/graphics/predictor/Average.java b/src/main/java/org/pdfbox/pdmodel/graphics/predictor/Average.java
new file mode 100644
index 0000000..46e65dc
--- /dev/null
+++ b/src/main/java/org/pdfbox/pdmodel/graphics/predictor/Average.java
@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2005, www.pdfbox.org
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of pdfbox; nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://www.pdfbox.org
+ *
+ */
+package org.pdfbox.pdmodel.graphics.predictor;
+
+/**
+ * We can use raw on the right hand side of
+ * the decoding formula because it is already decoded.
+ * 
+ * <code>average(i,j) = raw(i,j) + (raw(i-1,j)+raw(i,j-1)/2</code>
+ * 
+ * decoding
+ * 
+ * <code>raw(i,j) = avarage(i,j) - (raw(i-1,j)+raw(i,j-1)/2</code>
+ * 
+ * @author xylifyx@yahoo.co.uk
+ * @version $Revision: 1.2 $
+ */
+public class Average extends PredictorAlgorithm 
+{
+    /**
+     * Not an optimal version, but close to the def.
+     * 
+     * @see org.pdfbox.pdmodel.graphics.predictor.PredictorAlgorithm#encodeLine(byte[], byte[],
+     *      int, int, int, int)
+     */
+    public void encodeLine(byte[] src, byte[] dest, int srcDy, int srcOffset,
+            int destDy, int destOffset) 
+    {
+        int bpl = getWidth() * getBpp();
+        for (int x = 0; x < bpl; x++) 
+        {
+            dest[x + destOffset] = (byte) (src[x + srcOffset] - ((leftPixel(
+                    src, srcOffset, srcDy, x) + abovePixel(src, srcOffset,
+                    srcDy, x)) >>> 2));
+        }
+    }
+
+    /**
+     * @see org.pdfbox.pdmodel.graphics.predictor.PredictorAlgorithm#decodeLine(byte[], byte[],
+     *      int, int, int, int)
+     */
+    public void decodeLine(byte[] src, byte[] dest, int srcDy, int srcOffset,
+            int destDy, int destOffset) 
+    {
+        int bpl = getWidth() * getBpp();
+        for (int x = 0; x < bpl; x++) 
+        {
+            dest[x + destOffset] = (byte) (src[x + srcOffset] + ((leftPixel(
+                    dest, destOffset, destDy, x) + abovePixel(dest,
+                    destOffset, destDy, x)) >>> 2));
+        }
+    }
+}
-- 
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