Skip to content

Commit

Permalink
Use a smarter resize method, which enhances the image quality a lot,
Browse files Browse the repository at this point in the history 
especially for black and white images. Can be turned off in the renderer
if it costs too much performance.
Some small refactorings.
  • Loading branch information
@Borisvl
Borisvl committed Oct 9, 2011
1 parent a11424f commit 4bb808a
Showing 1 changed file with 143 additions and 6 deletions.
149 changes: 143 additions & 6 deletions src/com/sun/pdfview/PDFRenderer.java
View file
Expand Up @@ -23,14 +23,18 @@
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Paint;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.GeneralPath;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.ConvolveOp;
import java.awt.image.ImageObserver;
import java.awt.image.Kernel;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Iterator;
Expand All @@ -55,7 +59,7 @@ public class PDFRenderer extends BaseWatchable implements Runnable {
/** a weak reference to the image we render into. For the image
* to remain available, some other code must retain a strong reference to it.
*/
private WeakReference imageRef;
private WeakReference<BufferedImage> imageRef;
/** the graphics object for use within an iteration. Note this must be
* set to null at the end of each iteration, or the image will not be
* collected
Expand All @@ -78,6 +82,9 @@ public class PDFRenderer extends BaseWatchable implements Runnable {
private long then = 0;
/** the sum of all the individual dirty regions since the last update */
private Rectangle2D unupdatedRegion;
/** Use blur before image resize to enhance the result (Antialias) **/
public boolean useBlurResizingForImages = true;

/** how long (in milliseconds) to wait between image updates */
public static final long UPDATE_DURATION = 200;
public static final float NOPHASE = -1000;
Expand All @@ -86,6 +93,7 @@ public class PDFRenderer extends BaseWatchable implements Runnable {
public static final int NOCAP = -1000;
public static final float[] NODASH = null;
public static final int NOJOIN = -1000;


/**
* create a new PDFGraphics state
Expand Down Expand Up @@ -279,7 +287,7 @@ public Rectangle2D drawImage(PDFImage image) {
}

if (image.isImageMask()) {
bi = getMaskedImage(bi);
bi = getMaskedImage(bi);
}

/*
Expand All @@ -288,11 +296,124 @@ public Rectangle2D drawImage(PDFImage image) {
frame.pack();
frame.show();
*/

// long t = System.currentTimeMillis();
Rectangle r = g.getTransform().createTransformedShape(new Rectangle(0,0,1,1)).getBounds();
boolean isBlured = false;

//This is another possibility to enhance the quality of the images
//but it is slower (this could depend on the os and java version used)
//and the image quality is worse compared to the bluring method.
/*int it = 0;
int width = image.getWidth();
int height = image.getHeight();
while (width >= 2*r.getWidth() && height >= 2*r.getHeight()) {
width = width / 2;
height = height / 2;
BufferedImage blured = new BufferedImage(width,
height, bi.getType());
Graphics2D bg = (Graphics2D) blured.getGraphics();
bg.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
bg.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
bg.drawImage(bi, 0, 0, width,
height, null);
if (it > 0) bi.flush();
bi = blured;
it++;
}
at = new AffineTransform(1f / width, 0,
0, -1f / height,
0, 1);
*/

if (useBlurResizingForImages &&
bi.getType() != BufferedImage.TYPE_CUSTOM &&
image.getWidth() >= 1.75*r.getWidth() && image.getHeight() >= 1.75*r.getHeight()){

BufferedImageOp op;

final float maxFactor = 3.5f;
final boolean RESIZE = true;
if (image.getWidth() > maxFactor*r.getWidth() && image.getHeight() > maxFactor*r.getHeight()){
//First resize, otherwise we risk that we get out of heapspace
int newHeight = (int)Math.round(maxFactor*r.getHeight());
int newWidth = (int)Math.round(maxFactor*r.getWidth());
if (!RESIZE) {
newHeight = image.getHeight();
newWidth = image.getWidth();
}
BufferedImage blured = new BufferedImage(newWidth,
newHeight, bi.getType());
Graphics2D bg = (Graphics2D) blured.getGraphics();
bg.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
bg.drawImage(bi, 0, 0, newWidth, newHeight, null);
bi = blured;
at = new AffineTransform(1f / bi.getWidth(), 0,
0, -1f / bi.getHeight(),
0, 1);

final float weight = 1.0f/16.0f;
final float[] blurKernel = {
weight, weight, weight, weight,
weight, weight, weight, weight,
weight, weight, weight, weight,
weight, weight, weight, weight,
};
/*final float weight = 1.0f/32.0f;
final float[] blurKernel = {
weight, 2*weight, 2*weight, weight,
2*weight, 3*weight, 3*weight, 2*weight,
2*weight, 3*weight, 3*weight, 2*weight,
weight, 2*weight, 2*weight, weight,
};*/
/*final float[] blurKernel = {
weight, weight, weight, weight, weight,
weight, weight, weight, weight, weight,
weight, weight, weight, weight, weight,
weight, weight, weight, weight, weight,
weight, weight, weight, weight, weight
};*/
op = new ConvolveOp(new Kernel(4, 4, blurKernel), ConvolveOp.EDGE_NO_OP, null);
}
else {
/*final float weight = 1.0f/9.0f;
final float[] blurKernel = {
weight, weight, weight,
weight, weight, weight,
weight, weight, weight
};*/
final float weight = 1.0f/18.0f;
final float[] blurKernel = {
1*weight, 2*weight, 1*weight,
2*weight, 6*weight, 2*weight,
1*weight, 2*weight, 1*weight
};

op = new ConvolveOp(new Kernel(3, 3, blurKernel), ConvolveOp.EDGE_NO_OP, null);
}

BufferedImage blured = op.createCompatibleDestImage(bi, bi.getColorModel());

op.filter(bi, blured);
bi = blured;
isBlured = true;
}
this.g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));

//Image quality is better when using texturepaint instead of drawimage
//but it is also slower :(
/*g.setPaint(new TexturePaint(bi, new Rectangle2D.Float(0, 0, 1, -1)));
g.fillRect(0, 0, 1, 1);*/
this.g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
if (!this.g.drawImage(bi, at, null)) {
System.out.println("Image not completed!");
}
// System.out.println("Time : "+(System.currentTimeMillis()-t));

if (isBlured) bi.flush();

// get the total transform that was executed
AffineTransform bt = new AffineTransform(this.g.getTransform());
Expand Down Expand Up @@ -501,6 +622,15 @@ public GeneralPath getLastShape() {
return this.lastShape;
}

/**
* If exists, returns the image which is used by the renderer.
* @return a BufferedImage or null
*/
public BufferedImage getImage() {
if (this.imageRef == null) return null;
return (BufferedImage) this.imageRef.get();
}

/**
* Setup rendering. Called before iteration begins
*/
Expand Down Expand Up @@ -693,7 +823,7 @@ private void notifyObservers(BufferedImage bi, Rectangle2D region) {
}

synchronized (this.observers) {
for (Iterator i = this.observers.iterator(); i.hasNext();) {
for (Iterator<ImageObserver> i = this.observers.iterator(); i.hasNext();) {
ImageObserver observer = (ImageObserver) i.next();

boolean result = observer.imageUpdate(bi, flags,
Expand All @@ -714,9 +844,16 @@ private void notifyObservers(BufferedImage bi, Rectangle2D region) {
* that have a value in the image with the current paint
*/
private BufferedImage getMaskedImage(BufferedImage bi) {
// get the color of the current paint
Color col = (Color) this.state.fillPaint.getPaint();

// get the color of the current paint
final Paint paint = state.fillPaint.getPaint();
if (!(paint instanceof Color)) {
// TODO - support other types of Paint
return bi;
}

Color col = (Color) paint;

// format as 8 bits each of ARGB
int paintColor = col.getAlpha() << 24;
paintColor |= col.getRed() << 16;
Expand Down

0 comments on commit 4bb808a

Please sign in to comment.