Fix text stretching when printing to a receipt printer with Java - java

I am printing to some Epson receipt printers by implementing the Java Printable and placing my code into the print method. To draw the text to the printer I use Graphics2D.drawString. I am also drawing a rect to the printer to see how to compares to the text size when printing to other printers. When printing to the receipt printer the text on the paper is about double the width of printing to a laser printer or the XPS writer virtual print. Is this a problem with the way Java draws text to the Graphics2D object? I have the newest version of Java installed of 6 update 20.
Any Ideas of what to look into would be helpful.
Thanks.
Here the code I am using. With this example I am seeing the letter 'c' on the right edge of the rect when sending it to a XPS writer and if I print it to my receipt printer the 6 is on the right edge of the rect and you can tell the text is much wider then it should be. The rect seems to be the correct size.
I have tried changing the page and margin sizes but it does not seem to fix my text problem. I got these paper sizes and margins from how Microsoft Word is auto detecting the printer. Word prints the text correctly to the receipt printer.
public static void main(String[] args) {
PageFormat format = new PageFormat();
Paper paper = new Paper();
double paperWidth = 3.25;
double paperHeight = 11.69;
double leftMargin = 0.19;
double rightMargin = 0.25;
double topMargin = 0;
double bottomMargin = 0.01;
paper.setSize(paperWidth * 72.0, paperHeight * 72.0);
paper.setImageableArea(leftMargin * 72.0, topMargin * 72.0,
(paperWidth - leftMargin - rightMargin) * 72.0,
(paperHeight - topMargin - bottomMargin) * 72.0);
format.setPaper(paper);
PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet();
aset.add(OrientationRequested.PORTRAIT);
PrinterJob printerJob = PrinterJob.getPrinterJob();
Printable printable = new ReceiptPrintTest();
format = printerJob.validatePage(format);
printerJob.setPrintable(printable, format);
try {
printerJob.print(aset);
}
catch (Exception e) {
e.printStackTrace();
}
}
public class ReceiptPrintTest implements Printable {
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
if (pageIndex < 0 || pageIndex >= 1) {
return Printable.NO_SUCH_PAGE;
}
Graphics2D g2d = (Graphics2D) graphics;
g2d.translate(pageFormat.getImageableX(), pageFormat.getImageableY());
Font font = new Font("Arial",Font.PLAIN, 14);
g2d.setFont(font);
g2d.drawString("1234567890abcdefg", 50, 70);
g2d.drawRect(50, 0, 100, 50);
return Printable.PAGE_EXISTS;
}

Have you tried setting the font using setFont?

Related

Making text width flexible with ttf font

I am inquiring about two things. First I am having an ttf file and it is located in my macair drive. I do not want to add that file into my project structure. How can i import the True_type font from it. I have tried various ways to import it my Java program. e.g. public class TextFixer {
private static String[] names = { "iksswgrg.ttf" }; //this exists on my macair drive and i want to create font from it.
private static Map<String, Font> cache = new ConcurrentHashMap<String, Font>(names.length);
static {
for (String name : names) {
cache.put(name, getFont(name));
}
}
public static Font getFont(String name) {
Font font = null;
if (cache != null) {
if ((font = cache.get(name)) != null) {
return font;
}
}
String fName = "/fonts/" + name;
try {
InputStream is = TextFixer.class.getResourceAsStream(fName);
font = new Font("ttf", 0, 16);
//font = Font.createFont(Font.TRUETYPE_FONT, is);
} catch (Exception ex) {
ex.printStackTrace();
System.err.println(fName + " not loaded. Using serif font.");
font = new Font("serif", Font.PLAIN, 24);
}
return font;
}
2nd part is I want to create a String by using Graphics. First I need to have width that is of 130mm. The height of the displayed box will be the tallest character in the provided string. The font size is between 8 and 16. I have an enterprise project which take care of the height and size of the ttf. The problem i face is: I do not want to use swing/javafx libraries. I want to use Graphics library of Java, use Graphics2D to have a rectangle. How can i set its width to be precisely 130mm? Then I want to make that width flexible with according to the Font. I want to draw a string and the string should get adjusted/being flexible in the provided width. I am able to draw a string through g.drawString() but I am unable to see it on console. As I do not want to use Jframe or any Swing/javaFX libraries.
I know this seems a bit long but I hope I have explained it well enough. I desperately need help. Please let me know if you guys can help me out here.
Thanks in advance
First I am having an ttf file and it is located in my macair drive. I do not want to add that file into my project structure. How can i import the True_type font from it
This is more of a problem to do with "How do you reference a file on the file system" then "How do I load a font", because if you can solve the first, you can solve the second.
File fontFile = new File("some/relative/path/to/your/Font.tff");
or
File fontFile = new File("/some/absolute/path/to/your/Font.tff");
Personally, I like neither, as it it causes too much trouble (working directories, other systems, etc), I prefer to use embedded resources where possible or put the files in a common location.
For example {user.home}/AppData/Local/{application name} on Windows or on Mac you could use {user.home}/Library/Application Support/{application name}, then it doesn't matter where the program is executed from
Loading the font is relatively simple. For my example, I placed the font file in the working directory of the program
System.out.println(new File("Pacifico.ttf").exists());
Font font = Font.createFont(Font.TRUETYPE_FONT, new File("Pacifico.ttf"));
2nd part is I want to create a String by using Graphics. First I need to have width that is of 130mm. The height of the displayed box will be the tallest character in the provided string
This is much more complicated, as images are measured in pixels. In order to know how many pixels make up a given distance, we need to know the DPI of the image.
its 72DPI
Okay then, from that, we can calculate the number of pixels we need
public static double cmToPixel(double cm, double dpi) {
return (dpi / 2.54) * cm;
}
130mm (13 cm) comes out to be 368.503937007874 # 72dpi.
From this, we need to find the font point size for a given piece of text to fit within this range.
Now, there are a number of was you can do this, you could simply start at point 1 and perform a linear progression till you pass the range you're after. It's not exactly fast and, as you increase the size, it can become a little error prone.
I've opted for more of a divide and conquer approach
protected static int widthOfText(String text, Font font, float fontSize, Graphics2D g2d) {
font = font.deriveFont(fontSize);
FontMetrics fm = g2d.getFontMetrics(font);
int textWidth = fm.stringWidth(text);
return textWidth;
}
public static Float pointToFit(double width, String text, Font font, Graphics2D g2d, float min, float max) {
float fontSize = min + ((max - min) / 2f);
font = font.deriveFont(fontSize);
FontMetrics fm = g2d.getFontMetrics(font);
int textWidth = fm.stringWidth(text);
if (fontSize == min || fontSize == max) {
return fontSize;
}
if (textWidth < width) {
return pointToFit(width, text, font, g2d, fontSize, max);
} else if (textWidth > width) {
return pointToFit(width, text, font, g2d, min, fontSize);
}
return fontSize;
}
Important to note, it's not perfect, but it betters a linear progression :P
With this in hand, we can start calculating the required properties we need...
String text = "Happy, Happy, Joy, Joy";
double width = cmToPixel(13.0, 72.0);
BufferedImage img = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
float fontSize = pointToFit(width, text, font, g2d, 0, (float)width);
font = font.deriveFont(fontSize);
FontMetrics fm = g2d.getFontMetrics(font);
int height = fm.getHeight();
g2d.dispose();
Okay, so this creates a small (1x1) temporary image. We need Graphics context in order to calculate all the other properties. It then calculates the font point size, from it can then calculate the text height
With all that information in hand, we can get around to actually rendering the text...
img = new BufferedImage((int) Math.round(width), height, BufferedImage.TYPE_INT_ARGB);
g2d = img.createGraphics();
g2d.setFont(font);
fm = g2d.getFontMetrics();
g2d.setColor(Color.BLACK);
g2d.drawString(text, 0, fm.getAscent());
g2d.dispose();
Which will eventually output something like this...
I added the red border before I rendered the text so I could see how well it fitted.
Now, this is a really basic example, what this doesn't do is tell you when the text won't fit (ie, the point size is 1 or 0), you'll have to put traps in to catch that yourself
And, because I know you'll probably have lots of fun putting it together, my test code...
import java.awt.Color;
import java.awt.Font;
import java.awt.FontFormatException;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.GraphicsEnvironment;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.text.NumberFormat;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JOptionPane;
public class Test {
public static void main(String[] args) {
try {
System.out.println(new File("Pacifico.ttf").exists());
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
Font font = Font.createFont(Font.TRUETYPE_FONT, new File("Pacifico.ttf"));
String text = "Happy, Happy, Joy, Joy";
double width = cmToPixel(13.0, 72.0);
BufferedImage img = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
float fontSize = pointToFit(width, text, font, g2d, 0, (float) width);
System.out.println(width);
System.out.println(fontSize);
font = font.deriveFont(fontSize);
FontMetrics fm = g2d.getFontMetrics(font);
int height = fm.getHeight();
g2d.dispose();
img = new BufferedImage((int) Math.round(width), height, BufferedImage.TYPE_INT_ARGB);
g2d = img.createGraphics();
g2d.setColor(Color.RED);
g2d.drawRect(0, 0, img.getWidth() - 1, img.getHeight() - 1);
g2d.setFont(font);
fm = g2d.getFontMetrics();
g2d.setColor(Color.BLACK);
g2d.drawString(text, 0, fm.getAscent());
g2d.dispose();
JOptionPane.showConfirmDialog(null, new ImageIcon(img));
} catch (IOException | FontFormatException e) {
//Handle exception
}
}
public static Float pointToFit(double width, String text, Font font, Graphics2D g2d) {
return pointToFit(width, text, font, g2d, 0f, Float.MAX_VALUE);
}
protected static int widthOfText(String text, Font font, float fontSize, Graphics2D g2d) {
font = font.deriveFont(fontSize);
FontMetrics fm = g2d.getFontMetrics(font);
int textWidth = fm.stringWidth(text);
return textWidth;
}
public static Float pointToFit(double width, String text, Font font, Graphics2D g2d, float min, float max) {
float fontSize = min + ((max - min) / 2f);
NumberFormat nf = NumberFormat.getInstance();
font = font.deriveFont(fontSize);
FontMetrics fm = g2d.getFontMetrics(font);
int textWidth = fm.stringWidth(text);
if (fontSize == min || fontSize == max) {
return fontSize;
}
if (textWidth < width) {
return pointToFit(width, text, font, g2d, fontSize, max);
} else if (textWidth > width) {
return pointToFit(width, text, font, g2d, min, fontSize);
}
return fontSize;
}
public static double cmToPixel(double cm, double dpi) {
return (dpi / 2.54) * cm;
}
}

Java: Setting printable width (Pageformat)

I am attempting to print from my java application to a receipt printer,
the width of the receipt is 58mm, it seems that the margin is incorrect and printing with a margin of 1 inch on either side. This results in only 3 letters/numbers being printed and not the full line.
I can print from notepad successfully as I have manually adjusted the margin to 1.97mm on either side which seems to do the trick.
My code is as follows;
public int print(Graphics g, PageFormat pf, int pageIndex)
throws PrinterException {
Font font = new Font("MONOSPACED", Font.PLAIN, 10);
FontMetrics metrics = g.getFontMetrics(font);
int lineHeight = metrics.getHeight();
if (pageBreaks == null) {
initTextLines();
int linesPerPage = (int)(pf.getImageableHeight()/lineHeight);
int numBreaks = (textLines.length-1)/linesPerPage;
pageBreaks = new int[numBreaks];
for (int b=0; b<numBreaks; b++) {
pageBreaks[b] = (b+1)*linesPerPage;
}
}
if (pageIndex > pageBreaks.length) {
return NO_SUCH_PAGE;
}
/* User (0,0) is typically outside the imageable area, so we must
* translate by the X and Y values in the PageFormat to avoid clipping
* Since we are drawing text we
*/
Graphics2D g2d = (Graphics2D)g;
g2d.setFont(new Font("MONOSPACED", Font.PLAIN, 10));
g2d.translate(pf.getImageableX(), pf.getImageableY());
/* Draw each line that is on this page.
* Increment 'y' position by lineHeight for each line.
*/
int y = 0;
int start = (pageIndex == 0) ? 0 : pageBreaks[pageIndex-1];
int end = (pageIndex == pageBreaks.length)
? textLines.length : pageBreaks[pageIndex];
for (int line=start; line<end; line++) {
y += lineHeight;
g.drawString(textLines[line], 0, y);
}
/* tell the caller that this page is part of the printed document */
return PAGE_EXISTS;
}
I would also be grateful if you could help me align the text to the right hand side of the receipt to keep it uniformed with out other systems, however my main issue is the margin if that is sorted I will be over the moon :)
Thank You!
p.s. I am new to printing from java and have struggled, might have redundant code from copying online sources. I have adjusted the font so it is smaller, that did not help much.
I have figured out a workaround to get the desired results, just adding spaces before the text seems to work out well, I have also adjusted the code as follows;
public void print() throws PrintException, IOException {
String defaultPrinter =
PrintServiceLookup.lookupDefaultPrintService().getName();
System.out.println("Default printer: " + defaultPrinter);
PrintService service = PrintServiceLookup.lookupDefaultPrintService();
InputStream is = new ByteArrayInputStream(printableAmounts.getBytes("UTF8"));
PrintRequestAttributeSet pras = new HashPrintRequestAttributeSet();
pras.add(new Copies(1));
DocFlavor flavor = DocFlavor.INPUT_STREAM.AUTOSENSE;
Doc doc = new SimpleDoc(is, flavor, null);
DocPrintJob job = service.createPrintJob();
PrintJobWatcher pjw = new PrintJobWatcher(job);
job.print(doc, pras);
pjw.waitForDone();
is.close();
}
Seems to be a temporary solution but if nothing else comes up it will become permanent.

Issue with printing long receipts with java print() on thermal printer

I cannot print a thermal receipt (8cm) beyond (almost) A4 height paper size. Program only prints till (some default almost) A4 size is reached. and rest of receipt is lost.
Everything works fine with smaller receipts. problem occurs only with long receipts, where bill is cut short. I dynamically set paper height counting the lines to print. I also tried setting paper size and imageablearea to big size manually but in vain.
I tried to use Print.Book class object as well with no improvement.
(Note: Another program written in another language, prints same bill fine on same printer)
Please let me know if I am missing something or how to remove this limitation.
public void printReciept()
{
PrinterJob pj = PrinterJob.getPrinterJob();
pj.setPrintable(new BillPrintable(),getPageFormat(pj));
try {
pj.print();
}
catch (PrinterException ex) {
ex.printStackTrace();
}
}
public PageFormat getPageFormat(PrinterJob pj)
{
PageFormat pf = pj.defaultPage();
Paper paper = pf.getPaper();
double middleHeight =this.productList.size()*1.0; //dynamic----->change with the row count of jtable
double headerHeight = 5.0; //fixed----->but can be mod
double footerHeight = 5.0; //fixed----->but can be mod
double width = convert_CM_To_PPI(8); //printer know only point per inch.default value is 72ppi
double height = convert_CM_To_PPI(headerHeight+middleHeight+footerHeight);
paper.setSize(width, height);
paper.setImageableArea(
0,
10,
width,
height - convert_CM_To_PPI(1)
); //define boarder size after that print area width is about 180 points
pf.setOrientation(PageFormat.PORTRAIT); //select orientation portrait or landscape but for this time portrait
pf.setPaper(paper);
return pf;
}
public class BillPrintable implements Printable {
#Override
public int print(Graphics graphics, PageFormat pageFormat,int pageIndex)
throws PrinterException
{
String title[] = {"Product Name","Disc","Rate","Qty","AMT"};
int result = NO_SUCH_PAGE;
if (pageIndex == 0) {
Graphics2D g2d = (Graphics2D) graphics;
g2d.translate((int) pageFormat.getImageableX(),(int) pageFormat.getImageableY());
***** Below will be Code to print bill records *****
}
}

java PrinterJob not printing to fit paper

i am stuck currently when printing a jpeg file with the default printer. In my program when i select an image from a folder, i need to print it using the printer default settings (paper size, margins, orientation).
Currently i got this:
PrintService printService = PrintServiceLookup.lookupDefaultPrintService();
final BufferedImage image = ImageIO.read(new File("car.jpg"));
PrinterJob printJob = PrinterJob.getPrinterJob();
printJob.setPrintService(printService);
printJob.setPrintable(new Printable(){
#Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException{
if (pageIndex == 0) {
graphics.drawImage(image, 0, 0, (int)pageFormat.getWidth(), (int)pageFormat.getHeight(), null);
return PAGE_EXISTS;
else return NO_SUCH_PAGE;
}
}
printJob.print();
The default settings for my printer right now for size is: 10 x 15 cm (4 x 6 in)
but when i set my program to print the given image, it displays only a small section of the paper.
Please help me out.
EDIT
thanks everyone for their help, i managed to find the answer posted by another user at Borderless printing
Make sure that you are, first, translating the Graphics context to fit within inthe imagable area...
g2d.translate((int) pageFormat.getImageableX(),
(int) pageFormat.getImageableY());
Next, make sure you are using the imageableWidth and imageableHeight of the PageFormat
double width = pageFormat.getImageableWidth();
double height = pageFormat.getImageableHeight();
and not the width/height properties. Many of these things get translated from different contexts...
graphics.drawImage(image, 0, 0, (int)width, (int)height, null);
The getImageableWidth/Height returns the page size within the context of the page orientation
Printing pretty much assumes a dpi of 72 (don't stress, the printing API can handle much higher resolutions, but the core API assumes 72dpi)
This means that a page of 10x15cm should translate to 283.46456664x425.19684996 pixels. You can verify this information by using a System.out.println and dumping the results of getImageableWidth/Height to the console.
If you're getting different settings, it's possible that Java has overridden the default page properties
For example...
Fit image into the printing area
Setting print size of a jLabel and put a jRadiobutton on the print
You have two choices...
You could...
Show the PrintDialog and ensure that the correct page settings are selected
PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet();
aset.add(new PrinterResolution(300, 300, PrinterResolution.DPI));
aset.add(new MediaPrintableArea(0, 0, 150, 100, MediaPrintableArea.MM));
PrinterJob pj = PrinterJob.getPrinterJob();
pj.setPrintable(new PrintTask()); // You Printable here
if (pj.printDialog(aset)) {
try {
pj.print(aset);
} catch (PrinterException ex) {
ex.printStackTrace();
}
}
Or you could...
Just manually set the paper/page values manually...
public static void main(String[] args) {
PrinterJob pj = PrinterJob.getPrinterJob();
PageFormat pf = pj.defaultPage();
Paper paper = pf.getPaper();
// 10x15mm
double width = cmsToPixel(10, 72);
double height = cmsToPixel(15, 72);
paper.setSize(width, height);
// 10 mm border...
paper.setImageableArea(
cmsToPixel(0.1, 72),
cmsToPixel(0.1, 72),
width - cmsToPixel(0.1, 72),
height - cmsToPixel(0.1, 72));
// Orientation
pf.setOrientation(PageFormat.PORTRAIT);
pf.setPaper(paper);
PageFormat validatePage = pj.validatePage(pf);
pj.setPrintable(new Printable() {
#Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
// Your code here
return NO_SUCH_PAGE;
}
}, validatePage);
try {
pj.print();
} catch (PrinterException ex) {
ex.printStackTrace();
}
}
// The number of CMs per Inch
public static final double CM_PER_INCH = 0.393700787d;
// The number of Inches per CMs
public static final double INCH_PER_CM = 2.545d;
// The number of Inches per mm's
public static final double INCH_PER_MM = 25.45d;
/**
* Converts the given pixels to cm's based on the supplied DPI
*
* #param pixels
* #param dpi
* #return
*/
public static double pixelsToCms(double pixels, double dpi) {
return inchesToCms(pixels / dpi);
}
/**
* Converts the given cm's to pixels based on the supplied DPI
*
* #param cms
* #param dpi
* #return
*/
public static double cmsToPixel(double cms, double dpi) {
return cmToInches(cms) * dpi;
}
/**
* Converts the given cm's to inches
*
* #param cms
* #return
*/
public static double cmToInches(double cms) {
return cms * CM_PER_INCH;
}
/**
* Converts the given inches to cm's
*
* #param inch
* #return
*/
public static double inchesToCms(double inch) {
return inch * INCH_PER_CM;
}
It looks like you are printing the image with dimensions based on the PageFormat, rather than the actual image's dimensions, your drawImage() method should look something like this
graphics.drawImage(image, 0, 0, image.getWidth(), image.getHeight(), null)

Java Image Cut Off

Same question as last time but I will provide more detail.
I am currently rotating images using:
int rotateNum //in main class
double rotationRequired = Math.toRadians(rotateNum);
double locationX = img.getWidth(this) / 2;
double locationY = img.getHeight(this) / 2;
AffineTransform tx = AffineTransform.getRotateInstance(rotationRequired, locationX, locationY);
AffineTransformOp op = new AffineTransformOp(tx, AffineTransformOp.TYPE_BILINEAR);
g2d.drawImage(op.filter((BufferedImage)img, null), imgX, imgY, null);
And then I am actually rotating the image using:
double deltaX = (double)(imgY - otherImg.imgY);
double deltaY = (double)(imgX - otherImg.imgX);
rotateNum = (int)(180 * Math.atan2(deltaY, deltaX) / Math.PI);
My images vary in size. The smaller images don't get cut off (meaning cut off with white space) but the larger ones do, on the left or right side. Resizing the images doesn't work, and I clipped out the white rectangle around the image using the
GIMP.
Example Images:
Before(ignore the grey area to the left)
After:
See the cutoff at the side
The problem is your source image is not exactly quadratic. When you implement the AffineTransform rotation with at.rotate(-rad, width/2, height/2);, it is the same as:
at.translate(width/2,height/2);
at.rotate(rads);
at.translate(-width/2,-height/2);
So, when it execute the last line, it translates to the origin. And if the width is greater than y (or vice versa), than the origin of the transform will be translated to a smaller distance than the side of greater length.
For example, if your width is 30 and your height is 60, than the origin point will be set as (-15,-30) from where the transform was original set. So, when you translate it, say, 90 degrees, the image will end up with "width" 60 and "height" 30, but according to the origin point, the image original bottom will be drawn at (-30,0), so it overflows the AffineTransform in -15 in X axis. Then this part of image will cut.
To correct this, you can use the following code instead:
double degreesToRotate = 90;
double locationX =bufferedImage.getWidth() / 2;
double locationY = bufferedImage.getHeight() / 2;
double diff = Math.abs(bufferedImage.getWidth() - bufferedImage.getHeight());
//To correct the set of origin point and the overflow
double rotationRequired = Math.toRadians(degreesToRotate);
double unitX = Math.abs(Math.cos(rotationRequired));
double unitY = Math.abs(Math.sin(rotationRequired));
double correctUx = unitX;
double correctUy = unitY;
//if the height is greater than the width, so you have to 'change' the axis to correct the overflow
if(bufferedImage.getWidth() < bufferedImage.getHeight()){
correctUx = unitY;
correctUy = unitX;
}
int posAffineTransformOpX = posX-(int)(locationX)-(int)(correctUx*diff);
int posAffineTransformOpY = posY-(int)(locationY)-(int)(correctUy*diff);
//translate the image center to same diff that dislocates the origin, to correct its point set
AffineTransform objTrans = new AffineTransform();
objTrans.translate(correctUx*diff, correctUy*diff);
objTrans.rotate(rotationRequired, locationX, locationY);
AffineTransformOp op = new AffineTransformOp(objTrans, AffineTransformOp.TYPE_BILINEAR);
// Drawing the rotated image at the required drawing locations
graphic2dObj.drawImage(op.filter(bufferedImage, null), posAffineTransformOpX, posAffineTransformOpY, null);
Hope it help.
I imagine that it's not the size of the image that matters but rather its eccentricity: images that are more square-like have less of a problem then images that are either more fat or more thin.
I think that your problem is that your center of rotation shouldn't be [width / 2, height / 2] -- it's not that simple. Instead think of the image residing in the left upper portion of a large square the length of the square's side will be the image's width or height, whichever is larger. This is what gets rotated whenever you rotate your image.
For example, please see my reply here: https://stackoverflow.com/a/8720123/522444
This is something that java does unfortunately. One way to solve it is to make the shape a square, so that when rotating no clipping occurs.
This problem is covered in David's "Killer game programming in Java" book, books_google_killer+game+programming+clipping+rotating which is a great book if you want to do any java game programming (Even if it is a bit old).
Edit :: This converting of an image to a square can either be done to the raw image through image editing software, or through java itself. Perhaps roll your own rotating method which can check for such collisions..
Rotating the image may also affect the size of the image. Here is some code I found on the old Sun forums a long time ago (I forget the original poster). It recalculates the size required to display the image at its given angle of rotation:
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;
import java.io.*;
import java.net.*;
import javax.imageio.*;
import javax.swing.*;
public class RotateImage {
public static void main(String[] args) throws IOException {
URL url = new URL("https://blogs.oracle.com/jag/resource/JagHeadshot-small.jpg");
BufferedImage original = ImageIO.read(url);
GraphicsConfiguration gc = getDefaultConfiguration();
BufferedImage rotated1 = tilt(original, -Math.PI/2, gc);
BufferedImage rotated2 = tilt(original, +Math.PI/4, gc);
BufferedImage rotated3 = tilt(original, Math.PI, gc);
display(original, rotated1, rotated2, rotated3);
}
public static BufferedImage tilt(BufferedImage image, double angle, GraphicsConfiguration gc) {
double sin = Math.abs(Math.sin(angle)), cos = Math.abs(Math.cos(angle));
int w = image.getWidth(), h = image.getHeight();
int neww = (int)Math.floor(w*cos+h*sin), newh = (int)Math.floor(h*cos+w*sin);
int transparency = image.getColorModel().getTransparency();
System.out.println(transparency);
// BufferedImage result = gc.createCompatibleImage(neww, newh, transparency);
BufferedImage result = gc.createCompatibleImage(neww, newh, Transparency.TRANSLUCENT);
Graphics2D g = result.createGraphics();
g.translate((neww-w)/2, (newh-h)/2);
g.rotate(angle, w/2, h/2);
g.drawRenderedImage(image, null);
return result;
}
public static GraphicsConfiguration getDefaultConfiguration() {
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
return gd.getDefaultConfiguration();
}
public static void display(BufferedImage im1, BufferedImage im2, BufferedImage im3, BufferedImage im4) {
JPanel cp = new JPanel(new GridLayout(2,2));
addImage(cp, im1, "original");
addImage(cp, im2, "rotate -PI/2");
addImage(cp, im3, "rotate +PI/4");
addImage(cp, im4, "rotate PI");
JFrame f = new JFrame("RotateImage");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setContentPane(cp);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
static void addImage(Container cp, BufferedImage im, String title) {
JLabel lbl = new JLabel(new ImageIcon(im));
lbl.setBorder(BorderFactory.createTitledBorder(title));
cp.add(lbl);
}
}

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