Rasterize.java
import java.io.*;
import java.awt.color.*;
import java.awt.image.*;
import java.awt.geom.*;
import java.util.*;
import org.faceless.pdf2.*;
/**
* Testbed for benchmarking conversion from PDF to rasterized PDF.
*
* Usage: java Rasterize <file.pdf>
*
* Will test four options:
* 1. Render to hi-res B&W, then re-render to low-res color/gray if required
* 2. Render to low-res Color, then convert to gray or re-render as hi-res B&W if required
* 3. Render to hi-res Color then downsample as required
* 4. No change - render at 200dpi color.
*
* and save them as "out1.pdf", "out2.pdf", "out3.pdf" and "out4.pdf". While rendering
* one letter per page will be printed to System.out: C, G or B for Color, Grayscale or B&W.
*/
public class Rasterize {
public static void main(String[] args) throws IOException {
PDF pdf = new PDF(new PDFReader(new File(args[0])));
PDF rasterpdf;
if (pdf.getNumberOfPages() > 50) {
// Limit testing to 50 pages.
pdf.getPages().subList(50, pdf.getPages().size()).clear();
}
int colordpi = 200;
int bwdpi = 300;
long t1 = System.currentTimeMillis();
rasterpdf = rasterize(pdf, bwdpi, colordpi, ByRerenderToColor);
rasterpdf.render(new FileOutputStream("out1.pdf"));
long t2 = System.currentTimeMillis();
rasterpdf = rasterize(pdf, bwdpi, colordpi, ByRerenderTo1Bit);
rasterpdf.render(new FileOutputStream("out2.pdf"));
long t3 = System.currentTimeMillis();
rasterpdf = rasterize(pdf, bwdpi, colordpi, ByDownsampling);
rasterpdf.render(new FileOutputStream("out3.pdf"));
long t4 = System.currentTimeMillis();
rasterpdf = rasterize(pdf, bwdpi, colordpi, NoChange);
rasterpdf.render(new FileOutputStream("out4.pdf"));
long t5 = System.currentTimeMillis();
System.out.println("Rasterize took "+(t2-t1)+" "+(t3-t2)+" "+(t4-t3)+" "+(t5-t4));
}
public static PDF rasterize(PDF pdf, int bwdpi, int colordpi, Rasterizer rasterizer) {
PDF newpdf = new PDF();
PDFParser parser = new PDFParser(pdf);
List pages = pdf.getPages();
for (int i=0;i<pages.size();i++) {
OutputProfile profile = new OutputProfile(OutputProfile.Default);
parser.setOutputProfile(profile);
PDFPage page = pdf.getPage(i);
PagePainter painter = parser.getPagePainter(page);
BufferedImage bufimage = rasterizer.toBitmap(painter, profile, colordpi, bwdpi);
PDFImage pdfimage = null;
try {
pdfimage = new PDFImage(bufimage);
} catch (InterruptedException e) {
// Can't happen with BufferedImage
}
PDFPage newpage = newpdf.newPage((int)page.getWidth(), (int)page.getHeight());
newpage.drawImage(pdfimage, 0, 0, page.getWidth(), page.getHeight());
}
System.out.println();
return newpdf;
}
/**
* Given a 24-bit RGB image, optionally resize it or reduce the number of colors to 8 or 1
* @param image the image to be resize - must be 24-bit RGB with byte-based Raster
* @param indpi the DPI the image is currently in
* @param outdpi the DPI to convert the image to
* @param bpp the number of bits per pixel - 24 for RGB, 8 for Grayscale or 1 for B&W
* @return the modified image
*/
private static BufferedImage fixImage(BufferedImage image, int indpi, int outdpi, int bpp) {
// Assuming a DataBufferByte for both input and output image - this will always be
// the case in this eaxmple, but some ColorModels (eg ColorModel.getRGBdefault) use
// a DataBufferInt. So this is not a general purpose routine, but as used here this
// assumption makes the code a lot simpler and more efficient.
ColorModel cm = image.getColorModel();
WritableRaster raster = image.getRaster();
int w = raster.getWidth();
int h = raster.getHeight();
if (indpi != outdpi) {
double scale = (double)outdpi / indpi;
w *= scale;
h *= scale;
WritableRaster outraster = cm.createCompatibleWritableRaster(w, h);
AffineTransform tran = AffineTransform.getScaleInstance(scale, scale);
// This is typically hardware accelerated, so can't be beat for performance.
AffineTransformOp scaler = new AffineTransformOp(tran, AffineTransformOp.TYPE_BILINEAR);
scaler.filter(raster, outraster);
raster = outraster;
}
if (bpp == 8) {
// Remove color information but keep 1 pixel per byte - easy.
cm = PDFParser.GRAYSCALE;
WritableRaster outraster = cm.createCompatibleWritableRaster(w, h);
byte[] in = ((DataBufferByte)raster.getDataBuffer()).getData();
byte[] out = ((DataBufferByte)outraster.getDataBuffer()).getData();
int i = 0, j = 0;
while (i < in.length) {
int rgb = ((in[i++]&0xFF) << 16) | ((in[i++]&0xFF) << 8) | (in[i++]&0xFF);
// This is fast way of converting RGB to Grayscale. It's an integer
// based version of the standard PAL/NTSC grayscale formula:
// gray = 0.3red + 0.59green + 0.11blue
int gray = rgb==0xFFFFFF ? 255 : ((((rgb&0xFF0000)/850) + (((rgb<<8)&0xFF0000)/432) + ((rgb<<16)&0xFF0000)/2318)) >> 8;
out[j++] = (byte)gray;
}
raster = outraster;
} else if (bpp == 1) {
// Remove color information and reduce to 1 bit per pixel, or 7 pixels per byte.
// Still fairly simple, we just need to byte align each row.
cm = PDFParser.BLACKANDWHITE;
WritableRaster outraster = cm.createCompatibleWritableRaster(w, h);
byte[] in = ((DataBufferByte)raster.getDataBuffer()).getData();
byte[] out = ((DataBufferByte)outraster.getDataBuffer()).getData();
int i = 0, j = 0;
for (int y=0;y<h;y++) {
int x = 0, n = 0;
for (x=0;x<w;x++) {
int rgb = ((in[i++]&0xFF) << 16) | ((in[i++]&0xFF) << 8) | (in[i++]&0xFF);
int gray = rgb==0xFFFFFF ? 255 : ((((rgb&0xFF0000)/850) + (((rgb<<8)&0xFF0000)/432) + ((rgb<<16)&0xFF0000)/2318)) >> 8;
n <<= 1;
if (gray > 128) { // 128 is normal threshold, but you can adjust
n |= 1;
}
if ((x&7) == 7) { // Finished 8 pixel block - push it to output
out[j++] = (byte)n;
n = 0;
}
}
if ((x&7) != 7) { // Image isn't multiple of 8 wide - shift and push it to output
n <<= 8 - (x&7);
out[j++] = (byte)n;
}
}
raster = outraster;
} else if (bpp != 24) {
throw new IllegalArgumentException("bpp must be 24, 8 or 1");
}
if (raster != image.getRaster()) {
image = new BufferedImage(cm, raster, false, null);
}
return image;
}
//---------------------------------------------------------------------------
interface Rasterizer {
BufferedImage toBitmap(PagePainter painter, OutputProfile profile, int colordpi, int bwdpi);
}
static final Rasterizer ByDownsampling = new Rasterizer() {
public BufferedImage toBitmap(PagePainter painter, OutputProfile profile, int colordpi, int bwdpi) {
BufferedImage image = painter.getImage(bwdpi, PDFParser.RGB);
if (profile.isSet(OutputProfile.Feature.ColorImage) || profile.isSet(OutputProfile.Feature.ColorContent)) {
System.out.print("C");
image = fixImage(image, bwdpi, colordpi, 24);
} else if (profile.isSet(OutputProfile.Feature.GrayscaleImage) || profile.isSet(OutputProfile.Feature.GrayscaleContent)) {
System.out.print("G");
image = fixImage(image, bwdpi, colordpi, 8);
} else {
System.out.print("B");
image = fixImage(image, bwdpi, bwdpi, 1);
}
return image;
}
};
static final Rasterizer ByRerenderTo1Bit = new Rasterizer() {
public BufferedImage toBitmap(PagePainter painter, OutputProfile profile, int colordpi, int bwdpi) {
BufferedImage image = painter.getImage(colordpi, PDFParser.RGB);
if (profile.isSet(OutputProfile.Feature.ColorImage) || profile.isSet(OutputProfile.Feature.ColorContent)) {
System.out.print("C");
} else if (profile.isSet(OutputProfile.Feature.GrayscaleImage) || profile.isSet(OutputProfile.Feature.GrayscaleContent)) {
System.out.print("G");
image = fixImage(image, colordpi, colordpi, 8);
} else {
System.out.print("B");
image = painter.getImage(bwdpi, PDFParser.BLACKANDWHITE);
}
return image;
}
};
static final Rasterizer ByRerenderToColor = new Rasterizer() {
public BufferedImage toBitmap(PagePainter painter, OutputProfile profile, int colordpi, int bwdpi) {
BufferedImage image = painter.getImage(bwdpi, PDFParser.BLACKANDWHITE);
if (profile.isSet(OutputProfile.Feature.ColorImage) || profile.isSet(OutputProfile.Feature.ColorContent)) {
System.out.print("C");
image = painter.getImage(colordpi, PDFParser.RGB);
} else if (profile.isSet(OutputProfile.Feature.GrayscaleImage) || profile.isSet(OutputProfile.Feature.GrayscaleContent)) {
System.out.print("G");
image = painter.getImage(colordpi, PDFParser.GRAYSCALE);
} else {
System.out.print("B");
}
return image;
}
};
static final Rasterizer NoChange = new Rasterizer() {
public BufferedImage toBitmap(PagePainter painter, OutputProfile profile, int colordpi, int bwdpi) {
return painter.getImage(colordpi, PDFParser.RGB);
}
};
}