Extracted some bitmap handling functions from the PCL implementation into new BitmapImageUtil class.

Added limited support for more efficient image encoding in AFP. Where possible the raw image data from the RenderedImage is used. Limitations include:
- missing support for color lookup tables (IndexColorModel)
- monochrome images: additive/subtractive flag is not supported by the AFP library, yet.
Images with fewer bits per pixel than specified in the configuration are no longer blown up to 4, 8 or even 24 bits.

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@734737 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 253 insertions, 56 deletions

diff --git a/src/java/org/apache/fop/render/afp/AFPImageHandlerRenderedImage.java b/src/java/org/apache/fop/render/afp/AFPImageHandlerRenderedImage.java
index 28c942a08..b956d8264 100644
--- a/src/java/org/apache/fop/render/afp/AFPImageHandlerRenderedImage.java
+++ b/src/java/org/apache/fop/render/afp/AFPImageHandlerRenderedImage.java
@@ -19,24 +19,33 @@
 
 package org.apache.fop.render.afp;
 
+import java.awt.image.ColorModel;
 import java.awt.image.RenderedImage;
 import java.io.IOException;
 
 import org.apache.commons.io.output.ByteArrayOutputStream;
-import org.apache.fop.afp.AFPDataObjectInfo;
-import org.apache.fop.afp.AFPImageObjectInfo;
-import org.apache.fop.afp.AFPObjectAreaInfo;
-import org.apache.fop.afp.AFPPaintingState;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
 import org.apache.xmlgraphics.image.loader.ImageFlavor;
 import org.apache.xmlgraphics.image.loader.impl.ImageRendered;
 import org.apache.xmlgraphics.ps.ImageEncodingHelper;
 import org.apache.xmlgraphics.util.MimeConstants;
 
+import org.apache.fop.afp.AFPDataObjectInfo;
+import org.apache.fop.afp.AFPImageObjectInfo;
+import org.apache.fop.afp.AFPObjectAreaInfo;
+import org.apache.fop.afp.AFPPaintingState;
+import org.apache.fop.util.BitmapImageUtil;
+
 /**
  * PDFImageHandler implementation which handles RenderedImage instances.
  */
 public class AFPImageHandlerRenderedImage extends AFPImageHandler {
 
+    /** logging instance */
+    private static Log log = LogFactory.getLog(AFPImageHandlerRenderedImage.class);
+
     private static final ImageFlavor[] FLAVORS = new ImageFlavor[] {
         ImageFlavor.BUFFERED_IMAGE,
         ImageFlavor.RENDERED_IMAGE
@@ -67,22 +76,69 @@ public class AFPImageHandlerRenderedImage extends AFPImageHandler {
         int dataWidth = renderedImage.getWidth();
         imageObjectInfo.setDataWidth(dataWidth);
 
+        int maxPixelSize = paintingState.getBitsPerPixel();
+        if (paintingState.isColorImages()) {
+            maxPixelSize *= 3; //RGB only at the moment
+        }
+
+        ColorModel cm = renderedImage.getColorModel();
+        if (log.isTraceEnabled()) {
+            log.trace("ColorModel: " + cm);
+        }
+        int pixelSize = cm.getPixelSize();
+        if (cm.hasAlpha()) {
+            pixelSize -= 8;
+        }
+        //TODO Add support for CMYK images
+
+        byte[] imageData = null;
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        ImageEncodingHelper.encodeRenderedImageAsRGB(renderedImage, baos);
-        byte[] imageData = baos.toByteArray();
-
-        boolean colorImages = paintingState.isColorImages();
-        imageObjectInfo.setColor(colorImages);
-
-        // convert to grayscale
-        if (!colorImages) {
-            baos.reset();
-            int bitsPerPixel = paintingState.getBitsPerPixel();
-            imageObjectInfo.setBitsPerPixel(bitsPerPixel);
-            ImageEncodingHelper.encodeRGBAsGrayScale(
-                  imageData, dataWidth, dataHeight, bitsPerPixel, baos);
+        boolean allowDirectEncoding = true;
+        if (allowDirectEncoding && pixelSize <= maxPixelSize) {
+            //Attempt to encode without resampling the image
+            ImageEncodingHelper helper = new ImageEncodingHelper(renderedImage);
+            ColorModel encodedColorModel = helper.getEncodedColorModel();
+            boolean directEncode = true;
+            if (helper.getEncodedColorModel().getPixelSize() > maxPixelSize) {
+                directEncode = false; //pixel size needs to be reduced
+            }
+            if (BitmapImageUtil.getColorIndexSize(renderedImage) > 2) {
+                directEncode = false; //Lookup tables are not implemented, yet
+            }
+            if (BitmapImageUtil.isMonochromeImage(renderedImage)
+                    && BitmapImageUtil.isZeroBlack(renderedImage)) {
+                directEncode = false; //Passing additive/subtractive info not implemented, yet
+            }
+            if (directEncode) {
+                log.debug("Encoding image directly...");
+                imageObjectInfo.setBitsPerPixel(encodedColorModel.getPixelSize());
+                helper.encode(baos);
+                imageData = baos.toByteArray();
+            }
+        }
+        if (imageData == null) {
+            log.debug("Encoding image via RGB...");
+            //Convert image to 24bit RGB
+            ImageEncodingHelper.encodeRenderedImageAsRGB(renderedImage, baos);
             imageData = baos.toByteArray();
+
+            boolean colorImages = paintingState.isColorImages();
+            imageObjectInfo.setColor(colorImages);
+
+            // convert to grayscale
+            if (!colorImages) {
+                log.debug("Converting RGB image to grayscale...");
+                baos.reset();
+                int bitsPerPixel = paintingState.getBitsPerPixel();
+                imageObjectInfo.setBitsPerPixel(bitsPerPixel);
+                //TODO this should be done off the RenderedImage to avoid buffering the
+                //intermediate 24bit image
+                ImageEncodingHelper.encodeRGBAsGrayScale(
+                      imageData, dataWidth, dataHeight, bitsPerPixel, baos);
+                imageData = baos.toByteArray();
+            }
         }
+
         imageObjectInfo.setData(imageData);
 
         // set object area info
diff --git a/src/java/org/apache/fop/render/pcl/PCLGenerator.java b/src/java/org/apache/fop/render/pcl/PCLGenerator.java
index fbb9c6ad0..50cf622c7 100644
--- a/src/java/org/apache/fop/render/pcl/PCLGenerator.java
+++ b/src/java/org/apache/fop/render/pcl/PCLGenerator.java
@@ -47,6 +47,8 @@ import org.apache.commons.io.output.ByteArrayOutputStream;
 import org.apache.xmlgraphics.image.GraphicsUtil;
 import org.apache.xmlgraphics.util.UnitConv;
 
+import org.apache.fop.util.BitmapImageUtil;
+
 /**
  * This class provides methods for generating PCL print files.
  */
@@ -522,7 +524,7 @@ public class PCLGenerator {
      * @return the gray value
      */
     public final int convertToGray(int r, int g, int b) {
-        return (r * 30 + g * 59 + b * 11) / 100;
+        return BitmapImageUtil.convertToGray(r, g, b);
     }
 
     /**
@@ -574,13 +576,7 @@ public class PCLGenerator {
      * @return true if it's a monochrome image
      */
     public static boolean isMonochromeImage(RenderedImage img) {
-        ColorModel cm = img.getColorModel();
-        if (cm instanceof IndexColorModel) {
-            IndexColorModel icm = (IndexColorModel)cm;
-            return icm.getMapSize() == 2;
-        } else {
-            return false;
-        }
+        return BitmapImageUtil.isMonochromeImage(img);
     }
 
     /**
@@ -589,7 +585,7 @@ public class PCLGenerator {
      * @return true if it's a grayscale image
      */
     public static boolean isGrayscaleImage(RenderedImage img) {
-        return (img.getColorModel().getColorSpace().getNumComponents() == 1);
+        return BitmapImageUtil.isGrayscaleImage(img);
     }
 
     private MonochromeBitmapConverter createMonochromeBitmapConverter() {
@@ -766,22 +762,7 @@ public class PCLGenerator {
                 }
             }
             if (src == null) {
-                src = new BufferedImage(effDim.width, effDim.height,
-                        BufferedImage.TYPE_BYTE_GRAY);
-                Graphics2D g2d = src.createGraphics();
-                try {
-                    g2d.setBackground(Color.white);
-                    g2d.setColor(Color.black);
-                    g2d.clearRect(0, 0, effDim.width, effDim.height);
-
-                    AffineTransform at = new AffineTransform();
-                    double sx = effDim.getWidth() / orgDim.getWidth();
-                    double sy = effDim.getHeight() / orgDim.getHeight();
-                    at.scale(sx, sy);
-                    g2d.drawRenderedImage(img, at);
-                } finally {
-                    g2d.dispose();
-                }
+                src = BitmapImageUtil.convertToGrayscale(img, effDim);
             }
             MonochromeBitmapConverter converter = createMonochromeBitmapConverter();
             converter.setHint("quality", "false");
@@ -793,22 +774,9 @@ public class PCLGenerator {
             setTransparencyMode(sourceTransparency || mask != null, true);
             paintMonochromeBitmap(red, effResolution);
         } else {
-            //TODO untested!
             RenderedImage effImg = img;
             if (scaled) {
-                BufferedImage buf = new BufferedImage(effDim.width, effDim.height,
-                        BufferedImage.TYPE_BYTE_BINARY);
-                Graphics2D g2d = buf.createGraphics();
-                try {
-                    AffineTransform at = new AffineTransform();
-                    double sx = effDim.getWidth() / orgDim.getWidth();
-                    double sy = effDim.getHeight() / orgDim.getHeight();
-                    at.scale(sx, sy);
-                    g2d.drawRenderedImage(img, at);
-                } finally {
-                    g2d.dispose();
-                }
-                effImg = buf;
+                effImg = BitmapImageUtil.convertToMonochrome(img, effDim);
             }
             setSourceTransparencyMode(sourceTransparency);
             selectCurrentPattern(0, 0); //Solid black
diff --git a/src/java/org/apache/fop/util/BitmapImageUtil.java b/src/java/org/apache/fop/util/BitmapImageUtil.java
new file mode 100644
index 000000000..278587b64
--- /dev/null
+++ b/src/java/org/apache/fop/util/BitmapImageUtil.java
@@ -0,0 +1,173 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* $Id$ */
+
+package org.apache.fop.util;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics2D;
+import java.awt.geom.AffineTransform;
+import java.awt.image.BufferedImage;
+import java.awt.image.ColorModel;
+import java.awt.image.IndexColorModel;
+import java.awt.image.RenderedImage;
+
+/**
+ * Utility method for dealing with bitmap images.
+ */
+public class BitmapImageUtil {
+
+    /**
+     * Indicates whether an image is a monochrome (1 bit black and white) image.
+     * @param img the image
+     * @return true if it's a monochrome image
+     */
+    public static final boolean isMonochromeImage(RenderedImage img) {
+        return (getColorIndexSize(img) == 2);
+    }
+
+    /**
+     * Indicates whether a zero bit indicates a black/dark pixel for a monochrome image.
+     * @param img the image (must be 1 bit monochrome)
+     * @return true if a zero bit indicates a black/dark pixel, false for a white/bright pixel
+     */
+    public static final boolean isZeroBlack(RenderedImage img) {
+        if (!isMonochromeImage(img)) {
+            throw new IllegalArgumentException("Image is not a monochrome image!");
+        }
+        IndexColorModel icm = (IndexColorModel)img.getColorModel();
+        int gray0 = convertToGray(icm.getRGB(0));
+        int gray1 = convertToGray(icm.getRGB(1));
+        return gray0 < gray1;
+    }
+
+    /**
+     * Convert an RGB color value to a grayscale from 0 to 100.
+     * @param r the red component
+     * @param g the green component
+     * @param b the blue component
+     * @return the gray value
+     */
+    public static final int convertToGray(int r, int g, int b) {
+        return (r * 30 + g * 59 + b * 11) / 100;
+    }
+
+    /**
+     * Convert an RGB color value to a grayscale from 0 to 100.
+     * @param rgb the RGB value
+     * @return the gray value
+     */
+    public static final int convertToGray(int rgb) {
+        int r = (rgb & 0xFF0000) >> 16;
+        int g = (rgb & 0xFF00) >> 8;
+        int b = rgb & 0xFF;
+        return convertToGray(r, g, b);
+    }
+
+    /**
+     * Returns the size of the color index if the given image has one.
+     * @param img the image
+     * @return the size of the color index or 0 if there's no color index
+     */
+    public static final int getColorIndexSize(RenderedImage img) {
+        ColorModel cm = img.getColorModel();
+        if (cm instanceof IndexColorModel) {
+            IndexColorModel icm = (IndexColorModel)cm;
+            return icm.getMapSize();
+        } else {
+            return 0;
+        }
+    }
+
+    /**
+     * Indicates whether an image is a grayscale image.
+     * @param img the image
+     * @return true if it's a grayscale image
+     */
+    public static final boolean isGrayscaleImage(RenderedImage img) {
+        return (img.getColorModel().getColorSpace().getNumComponents() == 1);
+    }
+
+    /**
+     * Converts an image to sRGB. Optionally, the image can be scaled.
+     * @param img the image to be converted
+     * @param targetDimension the new target dimensions or null if no scaling is necessary
+     * @return the sRGB image
+     */
+    public static final BufferedImage convertTosRGB(RenderedImage img,
+            Dimension targetDimension) {
+        return convertAndScaleImage(img, targetDimension, BufferedImage.TYPE_INT_RGB);
+    }
+
+    /**
+     * Converts an image to a grayscale (8 bits) image. Optionally, the image can be scaled.
+     * @param img the image to be converted
+     * @param targetDimension the new target dimensions or null if no scaling is necessary
+     * @return the grayscale image
+     */
+    public static final BufferedImage convertToGrayscale(RenderedImage img,
+            Dimension targetDimension) {
+        return convertAndScaleImage(img, targetDimension, BufferedImage.TYPE_BYTE_GRAY);
+    }
+
+    /**
+     * Converts an image to a monochrome 1-bit image. Optionally, the image can be scaled.
+     * @param img the image to be converted
+     * @param targetDimension the new target dimensions or null if no scaling is necessary
+     * @return the monochrome image
+     */
+    public static final BufferedImage convertToMonochrome(RenderedImage img,
+            Dimension targetDimension) {
+        return convertAndScaleImage(img, targetDimension, BufferedImage.TYPE_BYTE_BINARY);
+    }
+
+    private static BufferedImage convertAndScaleImage(RenderedImage img,
+            Dimension targetDimension, int imageType) {
+        Dimension bmpDimension = targetDimension;
+        if (bmpDimension == null) {
+            bmpDimension = new Dimension(img.getWidth(), img.getHeight());
+        }
+        BufferedImage target = new BufferedImage(bmpDimension.width, bmpDimension.height,
+                imageType);
+        transferImage(img, target);
+        return target;
+    }
+
+    private static void transferImage(RenderedImage source, BufferedImage target) {
+        Graphics2D g2d = target.createGraphics();
+        try {
+            g2d.setBackground(Color.white);
+            g2d.setColor(Color.black);
+            g2d.clearRect(0, 0, target.getWidth(), target.getHeight());
+
+            AffineTransform at = new AffineTransform();
+            if (source.getWidth() != target.getWidth()
+                    || source.getHeight() != target.getHeight()) {
+                double sx = target.getWidth() / (double)source.getWidth();
+                double sy = target.getHeight() / (double)source.getHeight();
+                at.scale(sx, sy);
+            }
+            g2d.drawRenderedImage(source, at);
+        } finally {
+            g2d.dispose();
+        }
+    }
+
+
+}