printing bufferedimage to a printer - java

i have an application from which i want to print an image. The image is loaded as a BufferedImage object. The problem is, when i print the image (to the postscript or to the pdf file), the quality is really poor.
When i'm using some other tools (basically any picture viewer application which can print the image) the result is significantly better.
I know there can be some problems with the DPI vs resolution but i'm not exactly sure how to compute the correct values for printing.
I tried to google and tried some methods, but nothing seems to work as i expected.
Basicaly i just want to print an image (in resolution let's say 3000x2000) to a printer (with DPI for example 600x600).
This is how i create the print job:
PrintRequestAttributeSet printAttributes = new HashPrintRequestAttributeSet();
printAttributes.add(PrintQuality.HIGH);
printAttributes.add(new PrinterResolution(600, 600 PrinterResolution.DPI));
printAttributes.add(new Destination(URI.create("file:/tmp/test.ps")));
PageFormat pf = printerJob.defaultPage();
Paper paper = pf.getPaper();
double xMargin = 0.0;
double yMargin = 0.0;
paper.setImageableArea(xMargin, yMargin, paper.getWidth() - 2 * xMargin, paper.getHeight() - 2 * yMargin);
pf.setPaper(paper);
// create new Printable for the specified image
printerJob.setPrintable(PrintableImage.get(image), pf)
if (printerJob.printDialog(printAttributes)) {
printerJob.print(printAttributes);
}
Where image is BufferedImage and PrintableImage.get returns new instance which implements Printable
Then the actual print is doing this way (i let the commented code which i tried but didn't work for me)
#Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
if (image == null)
throw new PrinterException("no image specified to be printed");
// We have only one page, and 'page' is zero-based
if (pageIndex > 0) {
return NO_SUCH_PAGE;
}
// tranlate the coordinates (according to the orientations, margins, etc)
Graphics2D printerGraphics = (Graphics2D) graphics;
//g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
//g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
//g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
printerGraphics.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
// THIS IS A TEST - javax.printing api uses 72 DPI, but we have 600DPI set for the printer
//AffineTransform at = printerGraphics.getTransform();
//printerGraphics.scale((double)72 / (double)600, (double)72 / (double)600);
//printerGraphics.drawRenderedImage(image, null);
//printerGraphics.setTransform(at);
//if(printerGraphics != null)
//return PAGE_EXISTS;
double scale = 72.0 / 600.0;
Dimension pictureSize = new Dimension((int)Math.round(image.getWidth() / scale), (int) Math.round(image.getHeight() / scale));
// center the image horizontaly and verticaly on the page
int xMargin = (int) ((pageFormat.getImageableWidth() - image.getWidth()) / 2);
int yMargin = (int) ((pageFormat.getImageableHeight() - image.getHeight()) / 2);
xMargin = yMargin = 0;
System.out.println(String.format("page size [%.2f x %.2f], picture size [%.2f x %.2f], margins [%d x %d]", pageFormat.getImageableWidth(), pageFormat.getImageableHeight(), pictureSize.getWidth(), pictureSize.getHeight(), xMargin, yMargin));
printerGraphics.drawImage(image, xMargin, yMargin, (int)pageFormat.getWidth(), (int)pageFormat.getHeight(), null);
//printerGraphics.drawImage(image, 0, 0, null);
//printerGraphics.drawImage(image, xMargin, yMargin, pictureSize.width, pictureSize.height, null);
//printerGraphics.drawImage(image, xMargin, yMargin, (int) pageFormat.getImageableWidth(), (int) pageFormat.getImageableHeight(), 0, 0, pictureSize.width, pictureSize.height, null);
//printerGraphics.drawImage(image, 0, 0, (int) pageFormat.getWidth() - xMargin, (int) pageFormat.getHeight() - yMargin, 0, 0, pictureSize.width, pictureSize.height, null);
return PAGE_EXISTS;
}
Does anybody solves the same problem?
Any help would be appreciated.
Thanks
Matej

This is how I did it. It works smoothly. Note that this code snippet doesn't center the image.
public int print(Graphics g, PageFormat pageFormat, int pageIndex) throws PrinterException {
if (pageIndex > 0) {
return (NO_SUCH_PAGE);
} else {
double pageHeight = pageFormat.getImageableHeight(), pageWidth = pageFormat.getImageableWidth();
Graphics2D g2d = (Graphics2D) g;
g2d.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
if (pageHeight < image.getHeight() || pageWidth < image.getWidth()) {
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.drawImage(image, 0, 0, (int) pageWidth, (int) pageHeight - textSize, null);
} else {
g2d.drawImage(image, 0, 0, null);
}
g2d.dispose();
return (PAGE_EXISTS);
}
}

#Viktor Fonic
Thank you for this, I was searching a lot to do this!
You're solution works perfectly, but has a small error,
textSize was not declared, so:
int textSize = (int) (pageHeight - image.getHeight()*pageWidth/image.getWidth());

Related

How would I go about rendering a transparent and rotated image in Java?

I cannot seem to figure out how to draw a transparent and rotated image. I need to be able to draw an image that is transparent and rotated to a certain degree.
I tried this code:
// draws an image that is rotated to a certain degree
public static void drawRotatedImage(BufferedImage image_, int x, int y, int degrees, float scale) {
// graphics used for the utilities of drawing the image (processing)
Graphics2D utilGraphics;
// make rectangular image
int radius = (int) Math.sqrt(image_.getWidth() * image_.getWidth() + image_.getHeight() * image_.getHeight());
BufferedImage image1 = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_RGB);
utilGraphics = image1.createGraphics();
// centers image
utilGraphics.drawImage(image_, image1.getWidth() / 2 - image_.getWidth() / 2, image1.getHeight() / 2 - image_.getHeight() / 2, null);
// scale image
int nw = (int) (image1.getWidth() * scale);
int nh = (int) (image1.getHeight() * scale);
BufferedImage image = new BufferedImage(nw, nh, BufferedImage.TYPE_INT_RGB);
utilGraphics.drawImage(image1, 0, 0, nw, nh, null);
// Rotation information
double rotationRequired = Math.toRadians (degrees);
double locationX = image.getWidth() / 2;
double locationY = image.getHeight() / 2;
AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
ImageProducer filteredImgProd = new FilteredImageSource(op.filter(image, null).getSource(), filter);
Image transparentImg = Toolkit.getDefaultToolkit().createImage(filteredImgProd);
// Drawing the rotated image at the required drawing locations
g2d.drawImage(Toolkit.getDefaultToolkit().createImage(transparentImg.getSource()), x, y, null);
}
The filter variable is defined as:
private static final ImageFilter filter = new RGBImageFilter() {
int transparentColor = new Color(0, 0, 0, 0).getRGB() | 0x0000ffcc;
public final int filterRGB(int x, int y, int rgb) {
if ((rgb | 0x0000ffcc) == transparentColor) {
return 0x0000ffcc & rgb;
} else {
return rgb;
}
}
};
This ...
BufferedImage image = new BufferedImage(nw, nh, BufferedImage.TYPE_INT_RGB);
centeredGraphics.drawImage(image1, 0, 0, nw, nh, null);
You're creating a new BufferedImage (image), but you never actually paint anything to it, instead, you paint image1 to it's own Graphics context.
Now, if you wanted a transparent image, you should have used...
BufferedImage centeredImage = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_ARGB);
instead of...
BufferedImage centeredImage = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_RGB);
And I never used g2d.drawImage(Toolkit.getDefaultToolkit().createImage(transparentImg.getSource()), x, y, null); as it just doesn't make sense to me (transparentImg is already an Image 🤷‍♂️)
Now, having said all that, I would "suggest" you take each step individually, start by scaling the original image using something like Java: maintaining aspect ratio of JPanel background image and the rotate the image using something like Rotate a buffered image in Java (which will generate a image large enough to contain the rotated image)
Also, if you "create" a Graphics context, you should also dispose of it when you no longer need it, otherwise you could end up with a memory leak.
"Fixed" code...
Just to be clear, I would still recommend sing ARGB instead of RGB for centeredImage as your filter workflow never seemed to work for, but I started with a transparent image anyway
public Image rotateAndScaleImage(BufferedImage originalImage, int degrees, float scale) {
// make rectangular image
int radius = (int) Math.sqrt(originalImage.getWidth() * originalImage.getWidth() + originalImage.getHeight() * originalImage.getHeight());
BufferedImage centeredImage = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics = centeredImage.createGraphics();
// centers image
int xPos = (centeredImage.getWidth() - originalImage.getWidth()) / 2;
int yPos = (centeredImage.getHeight() - originalImage.getHeight()) / 2;
graphics.drawImage(originalImage, xPos, yPos, null);
graphics.dispose();
// scale image
int nw = (int) (centeredImage.getWidth() * scale);
int nh = (int) (centeredImage.getHeight() * scale);
BufferedImage image = new BufferedImage(nw, nh, BufferedImage.TYPE_INT_RGB);
graphics = image.createGraphics();
// No scaling is done ???
graphics.drawImage(centeredImage, 0, 0, nw, nh, null);
// Rotation information
double rotationRequired = Math.toRadians(degrees);
double locationX = centeredImage.getWidth() / 2;
double locationY = centeredImage.getHeight() / 2;
AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
ImageProducer filteredImgProd = new FilteredImageSource(op.filter(centeredImage, null).getSource(), filter);
Image transparentImg = Toolkit.getDefaultToolkit().createImage(filteredImgProd);
return transparentImg;
}
private static final ImageFilter filter = new RGBImageFilter() {
int transparentColor = new Color(0, 0, 0, 0).getRGB() | 0x0000ffcc;
public final int filterRGB(int x, int y, int rgb) {
if ((rgb | 0x0000ffcc) == transparentColor) {
return 0x0000ffcc & rgb;
} else {
return rgb;
}
}
};
Oh, and I'm returning an Image because I painted directly to a component for testing

Rotate BufferedImage with transparent background

I have an image with transparent background. I'd like to rotate this image to a specific angle and keep the transparent background for the resulting image. For this purpose I use the following method:
public static BufferedImage rotateImage(BufferedImage image, double angle, Color backgroundColor) {
System.out.println(image.getType());
double theta = Math.toRadians(angle);
double sin = Math.abs(Math.sin(theta));
double cos = Math.abs(Math.cos(theta));
int w = image.getWidth();
int h = image.getHeight();
int newW = (int) Math.floor(w * cos + h * sin);
int newH = (int) Math.floor(h * cos + w * sin);
BufferedImage tmp = new BufferedImage(newW, newH, image.getType());
Graphics2D g2d = tmp.createGraphics();
if (backgroundColor != null) {
g2d.setColor(backgroundColor);
g2d.fillRect(0, 0, newW, newH);
}
g2d.fillRect(0, 0, newW, newH);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g2d.translate((newW - w) / 2, (newH - h) / 2);
g2d.rotate(theta, w / 2, h / 2);
g2d.drawImage(image, 0, 0, null);
g2d.dispose();
return tmp;
}
I invoke it with background=null:
BufferedImage image = ImageIO.read(file);
rotateImage(image, 4, null);
ImageIO.write(bi, "PNG", new File("image.png"));
but the background of the resulting image.png is WHITE. What am I doing wrong and how to properly keep the transparent background for image.png?
I'm a bit puzzled about the behavior of Graphics.drawImage(). Maybe somebody else can comment about it.
However, Graphics2D.drawRenderedImage() works a treat. It takes an AffineTransform to control the rotation. The below example nicely works. You probably have additional requirement about the final image size and the location of the rotated image.
import javax.imageio.ImageIO;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
public class ImageRotation {
public static void main(String[] args) {
ImageRotation rotation = new ImageRotation();
rotation.rotate("input.png", 45, "output.png");
}
public void rotate(String inputImageFilename, double angle, String outputImageFilename) {
try {
BufferedImage inputImage = ImageIO.read(new File(inputImageFilename));
BufferedImage outputImage = rotateImage(inputImage, angle);
ImageIO.write(outputImage, "PNG", new File(outputImageFilename));
} catch (Exception e) {
throw new RuntimeException(e);
}
}
private BufferedImage rotateImage(BufferedImage sourceImage, double angle) {
int width = sourceImage.getWidth();
int height = sourceImage.getHeight();
BufferedImage destImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = destImage.createGraphics();
AffineTransform transform = new AffineTransform();
transform.rotate(angle / 180 * Math.PI, width / 2 , height / 2);
g2d.drawRenderedImage(sourceImage, transform);
g2d.dispose();
return destImage;
}
}
Update
While the above code works for most PNGs, it does not work for the image that alexanoid is using. I've analyzed the image:
It's a grayscale image without a color palette (PNG color type 0) .
It uses simple transparency with a 2 byte long tRNS chunk.
As far as I can tell that's perfectly legal. However, ImageIO does not implement this combination. If the image has no palette, it simply ignores the tRNS chunk and therefore ignores the transparency information. That's most likely a bug.
You basically have two options now:
Look for an alternative library to read PNG files.
Fix the transparency after you have read the PNG file. This only works if know that the image used the particular problematic format.
Input and output for working PNG files
Input image:
Ouptput Image:

Quality of Image after resize very low -- Java

In the script it is going from around the 300x300 mark down to 60x60. Need to improve the overall image quality as it is coming out very poorly at the moment.
public static Boolean resizeImage(String sourceImg, String destImg, Integer Width, Integer Height, Integer whiteSpaceAmount)
{
BufferedImage origImage;
try
{
origImage = ImageIO.read(new File(sourceImg));
int type = origImage.getType() == 0? BufferedImage.TYPE_INT_ARGB : origImage.getType();
int fHeight = Height;
int fWidth = Width;
int whiteSpace = Height + whiteSpaceAmount; //Formatting all to squares so don't need two whiteSpace calcs..
double aspectRatio;
//Work out the resized dimensions
if (origImage.getHeight() > origImage.getWidth()) //If the pictures height is greater than the width then scale appropriately.
{
fHeight = Height; //Set the height to 60 as it is the biggest side.
aspectRatio = (double)origImage.getWidth() / (double)origImage.getHeight(); //Get the aspect ratio of the picture.
fWidth = (int)Math.round(Width * aspectRatio); //Sets the width as created via the aspect ratio.
}
else if (origImage.getHeight() < origImage.getWidth()) //If the pictures width is greater than the height scale appropriately.
{
fWidth = Width; //Set the height to 60 as it is the biggest side.
aspectRatio = (double)origImage.getHeight() / (double)origImage.getWidth(); //Get the aspect ratio of the picture.
fHeight = (int)Math.round(Height * aspectRatio); //Sets the height as created via the aspect ratio.
}
int extraHeight = whiteSpace - fHeight;
int extraWidth = whiteSpace - fWidth;
BufferedImage resizedImage = new BufferedImage(whiteSpace, whiteSpace, type);
Graphics2D g = resizedImage.createGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, whiteSpace, whiteSpace);
g.setComposite(AlphaComposite.Src);
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.drawImage(origImage, extraWidth/2, extraHeight/2, fWidth, fHeight, null);
g.dispose();
ImageIO.write(resizedImage, "jpg", new File(destImg));
}
catch (IOException ex)
{
return false;
}
return true;
}
Really just need to know if their is something I can plug in that will bump up the quality or if I need to look at something else entirely.
EDIT: Picture comparison.
Source, just picked a random washing machine from google.
http://www.essexappliances.co.uk/images/categories/washing-machine.jpg
The same picture converted in Photoshop to what I need it to be.
http://imgur.com/78B1p
What it looks like being converted like this.
http://imgur.com/8WlXD
Scaling an image down over a large range is inherently dangerous (from the point of view of quality), especially using a single step.
The recommended method is to use a divide and conquer method. Basically, you scale the image down in steps of 50% until you reach your desired size.
So, I took the original image of 650x748 and scaled it down to fit within a 60x60 region (52x60).
Divide and conquer compared to one step...
public class TestImageResize {
public static void main(String[] args) {
new TestImageResize();
}
public TestImageResize() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new ScalePane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ScalePane extends JPanel {
private BufferedImage original;
private BufferedImage scaled;
public ScalePane() {
try {
original = ImageIO.read(new File("path/to/master.jpg"));
scaled = getScaledInstanceToFit(original, new Dimension(60, 60));
ImageIO.write(scaled, "jpg", new File("scaled.jpg"));
BufferedImage image = new BufferedImage(52, 60, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = image.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.drawImage(original, 0, 0, 52, 60, this);
g2d.dispose();
ImageIO.write(image, "jpg", new File("test.jpg"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
#Override
public Dimension getPreferredSize() {
Dimension size = super.getPreferredSize();
if (original != null) {
if (scaled != null) {
size.width = original.getWidth() + scaled.getWidth();
size.height = original.getHeight();
} else {
size.width = original.getWidth();
size.height = original.getHeight();
}
}
return size;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if (original != null) {
int x = 0;
int y = (getHeight() - original.getHeight()) / 2;;
if (scaled != null) {
x = (getWidth() - (original.getWidth() + scaled.getWidth())) / 2;
} else {
x = (getWidth() - original.getWidth()) / 2;
}
g2d.drawImage(original, x, y, this);
if (scaled != null) {
x += original.getWidth();
y = (getHeight() - scaled.getHeight()) / 2;
g2d.drawImage(scaled, x, y, this);
}
}
g2d.dispose();
}
public BufferedImage getScaledInstanceToFit(BufferedImage img, Dimension size) {
float scaleFactor = getScaleFactorToFit(img, size);
return getScaledInstance(img, scaleFactor);
}
public float getScaleFactorToFit(BufferedImage img, Dimension size) {
float scale = 1f;
if (img != null) {
int imageWidth = img.getWidth();
int imageHeight = img.getHeight();
scale = getScaleFactorToFit(new Dimension(imageWidth, imageHeight), size);
}
return scale;
}
public float getScaleFactorToFit(Dimension original, Dimension toFit) {
float scale = 1f;
if (original != null && toFit != null) {
float dScaleWidth = getScaleFactor(original.width, toFit.width);
float dScaleHeight = getScaleFactor(original.height, toFit.height);
scale = Math.min(dScaleHeight, dScaleWidth);
}
return scale;
}
public float getScaleFactor(int iMasterSize, int iTargetSize) {
float scale = 1;
if (iMasterSize > iTargetSize) {
scale = (float) iTargetSize / (float) iMasterSize;
} else {
scale = (float) iTargetSize / (float) iMasterSize;
}
return scale;
}
public BufferedImage getScaledInstance(BufferedImage img, double dScaleFactor) {
BufferedImage imgBuffer = null;
imgBuffer = getScaledInstance(img, dScaleFactor, RenderingHints.VALUE_INTERPOLATION_BILINEAR, true);
return imgBuffer;
}
protected BufferedImage getScaledInstance(BufferedImage img, double dScaleFactor, Object hint, boolean higherQuality) {
int targetWidth = (int) Math.round(img.getWidth() * dScaleFactor);
int targetHeight = (int) Math.round(img.getHeight() * dScaleFactor);
int type = (img.getTransparency() == Transparency.OPAQUE)
? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
BufferedImage ret = (BufferedImage) img;
if (targetHeight > 0 || targetWidth > 0) {
int w, h;
if (higherQuality) {
w = img.getWidth();
h = img.getHeight();
} else {
w = targetWidth;
h = targetHeight;
}
do {
if (higherQuality && w > targetWidth) {
w /= 2;
if (w < targetWidth) {
w = targetWidth;
}
}
if (higherQuality && h > targetHeight) {
h /= 2;
if (h < targetHeight) {
h = targetHeight;
}
}
BufferedImage tmp = new BufferedImage(Math.max(w, 1), Math.max(h, 1), type);
Graphics2D g2 = tmp.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, hint);
g2.drawImage(ret, 0, 0, w, h, null);
g2.dispose();
ret = tmp;
} while (w != targetWidth || h != targetHeight);
} else {
ret = new BufferedImage(1, 1, type);
}
return ret;
}
}
}
You may, also, find The Perils of Image.getScaledInstance() of interest.
The issue you are seeing is actually related to the resampling filter used for downscaling. Obviously, the one used by your library is a bad one for the situation. Nearest neighbor, bilinear and bicubic are typical bad examples to be used when downscaling. I don't know the exact resampling filter Photoshop uses, but I used 3-lobed lanczos and got the following result:
So, to solve your problem, you need to use a smarter resampling filter.
dutchman, this is why I maintain the imgscalr library -- to make this kind of stuff painfully easy.
In your example, a single method call would do the trick, right after your first ImageIO.read line:
origImage = ImageIO.read(new File(sourceImg));
you can do the following to get what you want (javadoc for this method):
origImage = Scalr.resize(origImage, Method.ULTRA_QUALITY, 60);
and if that still looked a little jagged (because you are removing so much information from the image, you can add the following OP to the command to apply a light anti-aliasing filter to the image so it looks smoother):
origImage = Scalr.resize(origImage, Method.ULTRA_QUALITY, 60, Scalr.OP_ANTIALIAS);
That will replace all the remainder of the code logic you have. The only other thing I would recommend is saving out your really small samples as PNG's so there is no more compression/lossy conversion done on the image OR make sure you use little to none compression on the JPG if you really want it in JPG format. (Here is an article on how to do it; it utilizes the ImageWriteParam class)
imgscalr is licensed under an Apache 2 license and hosted on GitHub so you can do what you want with it; it also includes asynchronous scaling support if you are using the library in a server-side app and queuing up huge numbers of scaling operations and don't want to kill the server.
As already stated, Java's Graphics2D does not provide a very good algorithm for down-scaling. If you don't want to implement a sophisticated algorithm yourself you could try out the current open source libs specialized for this: Thumbnailator, imgscalr and a Java interface for ImageMagick.
While researching for a private project I tried them out (except ImageMagick) and here are the visual results with Photoshop as reference:
A. Thumbnailator 0.4.8 with default settings (no additional internal resizing)
B. imgscalr 4.2 with ULTRA_QUALTY setting
C. Photoshop CS5 bicubic filter (save for web)
D. Graphics2d with all HQ render hints
Here is the used code
Thumbnailator and PS create similar results, while imgscalr seems to be softer. It is subjective which one of the libs creates the preferable results. Another point to consider though is the performance. While Thumbnailator and Graphics2d have similar runtime, imgscalr is considerably slower (with ULTRA_QUALITY) in my benchmarks.
For more info, read this post providing more detail on this matter.

Printing jpanel data where page width is greater than height

In my desktop application i need to print jPanel data on dot matrix printer where paper size should be 10x6. In java we have a restriction that width should not greater than height. But how can i accomplish my task by crossing this limit. If i set the page format with height is smaller than width it is treating it as A4 paper and feed the bottom of the paper.
If I didn't specify the page format it is printing fine but giving lot of margin(top,bottom,left,right). I am unable to change the margins. If set only the margins it is treating page as A4 and giving feed at bottom.
I need to print the data on pre printed page with alignment. Is there any other way to do this. Can I use Landscape, If so how to control the text flow (from bottom to top - X axis).
This is my code
PrinterJob job = PrinterJob.getPrinterJob();
PageFormat pageFormat = job.defaultPage();
pageFormat.setOrientation(PageFormat.LANDSCAPE);
job.setPrintable(this,pageFormat);
try {
job.print();
} catch (PrinterException ex) {
System.out.println(ex);
}
paint method
public int print(Graphics g, PageFormat pf, int page) throws PrinterException {
if (page > 0) {
return NO_SUCH_PAGE;
}
g.setFont(new java.awt.Font("Sans Serif", java.awt.Font.PLAIN, 10));
Graphics2D g2d = (Graphics2D)g;
AffineTransform old = g2d.getTransform();
if (pf.getOrientation() == PageFormat.LANDSCAPE) {
g2d.rotate( -Math.PI / 2, 0, 0);
g2d.translate( -pf.getImageableWidth(), 0);
}
else {
g2d.rotate(Math.PI / 2, 0, 0);
g2d.translate(0, -pf.getImageableHeight());
}
jPanel1.printAll(g2d);
g2d.setTransform(old);
//g2d.translate(70, 30);
return PAGE_EXISTS;
}
Thanks in advance.
Set PageFormat's orientation to landscape and rotate the content. In the print() method rotate and translate the content.
Graphics2D g2d = (Graphics2D) g;
AffineTransform old = g2d.getTransform();
if (contentOrientation == ORIENTATION_DOWN_UP) {
g2d.rotate( -Math.PI / 2, 0, 0);
g2d.translate( -w, 0);
}
else {
g2d.rotate(Math.PI / 2, 0, 0);
g2d.translate(0, -h);
}
//paint all your content here
g2d.setTransform(old);

High Quality thumbnail in java

I tried the code below to generate a thumbnail.
I am able to get the thumbnail but the quality is not there. Please can any one help me in this one to generate a high quality thumbnail? The original image is high quality.
BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = thumbImage.createGraphics();
graphics2D.setBackground(Color.WHITE);
graphics2D.setPaint(Color.WHITE);
graphics2D.fillRect(0, 0, thumbWidth, thumbHeight);
graphics2D.setComposite(AlphaComposite.Src);
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);
graphics2D.dispose();
File file = new File(thumbnailFile);
if (javax.imageio.ImageIO.write(thumbImage, "JPG", file))
return file;
You might want to take a look at this: http://download.oracle.com/javase/tutorial/uiswing/components/icon.html
http://download.oracle.com/javase/tutorial/uiswing/examples/components/IconDemoProject/src/components/IconDemoApp.java
I used that as a reference for doing something similar before.
I had the same problem and found this great article with sample code and sample images at the end:
http://today.java.net/pub/a/today/2007/04/03/perils-of-image-getscaledinstance.html
check this I found best jar file here
public static javaxt.io.Image resizeThumbnailImage(javaxt.io.Image image, int width, int height) {
Integer imgWidth = image.getWidth();
Integer imgHeight = image.getHeight();
Double imgRatio = (imgWidth.doubleValue() / imgHeight.doubleValue());
logger.info("\n======= imgRatio " + imgRatio);
if (imgRatio >= 2) {
image.setWidth(width - 1);
} else if (imgRatio < 1) {
image.setHeight(300);
} else {
Double expectedHeight = (imgRatio * (height / ProjectConstant.THUMBNAIL_IMG_ASPECT_RATIO));
image.setHeight(expectedHeight.intValue());
if (image.getWidth() > width) {
image.setWidth(width - 20);
}
}
logger.info("=======after Processing image Width " + image.getWidth()+" Hight "+image.getHeight());
return image;
}
my constant
public static final double THUMBNAIL_IMG_ASPECT_RATIO = 1.4;

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