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How to rotate around the image center by itext?

double degPi = degrees * Math.PI / 180;
double a = Math.cos(degPi)*tImgCover.getScaledHeight();
double b = Math.sin(degPi)*tImgCover.getScaledWidth();
double c = -Math.sin(degPi) * tImgCover.getScaledHeight();
double d = Math.cos(degPi)* tImgCover.getScaledWidth();
double e = absX;
double f = absY;
contentByte.addImage(imgae, a, b, c, d, e, f);/*add image*/
How to rotate around the image center by itext?

If we have an Image image and coordinates x, y, we can draw the image without rotation with its lower left corner at the given coordinates like this
contentByte.addImage(image, image.getWidth(), 0, 0, image.getHeight(), x, y);
A bitmap image from the resources has a size of 1x1 with the coordinate origin at its lower left. Thus, this operation stretches the image to its correct size and moves it so its lower left is at the given coordinates.
If we want to draw the same image as if the one drawn above was rotated around its center by an angle rotate, therefore, we can do this by moving the 1x1 image so that the origin is in its center, stretch it to its correct size, rotate it, and then move the origin (which still is at the center of the rotated image) to the center of the unrotated image. These operations are easier to express using AffineTransform instances (from package com.itextpdf.awt.geom) instead number tupels. Thus:
// Draw image as if the previous image was rotated around its center
// Image starts out being 1x1 with origin in lower left
// Move origin to center of image
AffineTransform A = AffineTransform.getTranslateInstance(-0.5, -0.5);
// Stretch it to its dimensions
AffineTransform B = AffineTransform.getScaleInstance(image.getWidth(), image.getHeight());
// Rotate it
AffineTransform C = AffineTransform.getRotateInstance(rotate);
// Move it to have the same center as above
AffineTransform D = AffineTransform.getTranslateInstance(x + image.getWidth()/2, y + image.getHeight()/2);
// Concatenate
AffineTransform M = (AffineTransform) A.clone();
M.preConcatenate(B);
M.preConcatenate(C);
M.preConcatenate(D);
//Draw
contentByte.addImage(image, M);
(AddRotatedImage.java test method testAddRotatedImage)
For example drawing both images using
int x = 200;
int y = 300;
float rotate = (float) Math.PI / 3;
results in something like this:
With a Flip
The OP asked in a comment
how to add rotate and flip image？
For this you simply insert a mirroring affine transformation into the sequence of transformations above.
Unfortunately the OP did not mention which he meant a horizontal or a vertical flip. But as changing the rotation angle accordingly transforms one in the other, that isn't really necessary, either.
// Draw image as if the previous image was flipped and rotated around its center
// Image starts out being 1x1 with origin in lower left
// Move origin to center of image
AffineTransform A = AffineTransform.getTranslateInstance(-0.5, -0.5);
// Flip it horizontally
AffineTransform B = new AffineTransform(-1, 0, 0, 1, 0, 0);
// Stretch it to its dimensions
AffineTransform C = AffineTransform.getScaleInstance(image.getWidth(), image.getHeight());
// Rotate it
AffineTransform D = AffineTransform.getRotateInstance(rotate);
// Move it to have the same center as above
AffineTransform E = AffineTransform.getTranslateInstance(x + image.getWidth()/2, y + image.getHeight()/2);
// Concatenate
AffineTransform M = (AffineTransform) A.clone();
M.preConcatenate(B);
M.preConcatenate(C);
M.preConcatenate(D);
M.preConcatenate(E);
//Draw
contentByte.addImage(image, M);
(AddRotatedImage.java test method testAddRotatedFlippedImage)
The result with the same image as above:
With Interpolation
The OP asked in a yet another comment
How anti aliasing ?
The iText Image class knows an Interpolation property. By setting it to true (before adding the image to the document, obviously),
image.setInterpolation(true);
low resolution images are subject to interpolation when drawn.
E.g. using a 2x2 image with differently colored pixels instead of the image of Willi, you get the following results, first without interpolation, then with interpolation:
Confer the AddRotatedImage.java test testAddRotatedInterpolatedImage which adds this image:
Beware: iText Image property Interpolation effectively sets the Interpolate entry in the PDF image dictionary. The PDF specification notes in this context:
NOTE A conforming Reader may choose to not implement this feature of PDF, or may use any specific implementation of interpolation that it wishes.
Thus, on some viewers interpolation may occur differently than in your viewer, maybe even not at all. If you need a specific kind of interpolation on every viewer, upscale the image with the desired amount of interpolation / anti-aliasing before loading it into an iText Image.

public static BufferedImage rotateClockwise90( BufferedImage inputImage ){
int width = inputImage.getWidth();
int height = inputImage.getHeight();
BufferedImage returnImage = new BufferedImage( height, width , inputImage.getType() );
for( int x = 0; x < width; x++ ) {
for( int y = 0; y < height; y++ ) {
returnImage.setRGB( height-y-1, x, inputImage.getRGB( x, y ) );
}
}
return returnImage;
}

Image/Texture scroll/shift (wrap)

Does anyone know whether libGDX has a method for scrolling/shifting an image/texture within itself?
To explain; I would like to be able to scroll the contents (pixels) of an image, either vertically or horizontally within its own region. For example, if an image is shifted 1 pixel to the right, all pixels move 1 to the right and those on the right-most-edge are wrapped to the left-most-edge. The image size does not change, only the positioning of the pixels within it change.
I have mainly been working with the Sprite class, it can do a lot (scale, rotate, etc) but shift/scroll as I need it, isn't there.
Before writting the method myself, I thought I'd ask here...
The following worked for me, this was provided by Kush:
float delta = 0f;
// In the Actors act method
delta += Gdx.graphics.getDeltaTime();
// Horizontal
batch.draw(texture, 0, 0, width, height, 0 + delta * 10, 1, 1 + delta * 10, 0);
// Vertical
batch.draw(texture, 0, 0, width, height, 1, 0 + delta * 10, 0, 1 + delta * 10);

You won't need Sprite for this, draw directly Texture using batch. For wrapping first set
Texture texture = new Texture("example.png");
texture.setWrap(TextureWrap.Repeat, TextureWrap.Repeat);
then draw using uv
batch.draw(texture, x, y, width, height, u, v, u2, v2);
or any other method that suits you in SpriteBatch.

Graphics2D - Text is HUGE in scaled coordinate space

The first "foo" is normal, but the second one is so huge I can only see the base of the "f". The font-size is the default.
BufferedImage image = new BufferedImage(500, 500, BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = image.createGraphics();
Shape ellipse = new Ellipse2D.Double(0, 0, 1.0, 1.0);
g2.setPaint(Color.RED);
g2.drawString("foo", 100, 100);
g2.scale(500.0f / length, 500.0f / length);
g2.drawString("foo", 1, 1);
Changing the font size will not help because it only allows int sizes and the size that would make sense for the scale is something like 0.02.
The reason I need to draw the text while in scaled space is because I am drawing a grid of nodes and I want to scale the coordinates to the number of nodes in each dimension. That way I do not have to do complicated calculations.
I need the text to label the edges.
Update: I am able to get the text by doing the following sequence each time I want to draw the text: saving the transform, translating to the desired location in scaled space, unscaling, drawing the text at (0, 0), and restoring the transform.

You can use Font method
public Font deriveFont(float size)
to obtain desired font size font. Guess the 0.02 shoud be fine.

How to rotate image at a specific point by a certain angle in java?

I want to rotate an image about a specific pixel position and not about the centre of the image. I want to rotate the image by certain degrees less than 90. I've made use of rotate function of the graphics class but i get the image blurred when rotated. How to remove this blur? Is there a specific function for this? This is the code i am using right now:
BufferedImage oldImage = ImageIO.read(new File("C:/omr/OMR_Rotation_1.jpg"));
BufferedImage newImage = new BufferedImage(oldImage.getWidth(), oldImage.getHeight(),oldImage.getType());
Graphics2D graphics = (Graphics2D) newImage.getGraphics();
graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_DEFAULT);
graphics.rotate(Math.toRadians(-2.3), newImage.getWidth() / 2, newImage.getHeight() / 2);
graphics.translate((newImage.getWidth() - oldImage.getWidth()) / 2, (newImage.getHeight() - oldImage.getHeight()) / 2);
//graphics.drawImage(oldImage, 0, 0, oldImage.getWidth(), oldImage.getHeight(), null);
graphics.drawImage(oldImage, null, 0, 0);
ImageIO.write(newImage, "JPG", new File("C:/omr/OMR_Rotation_2.jpg"));
graphics.translate((newImage.getWidth() - oldImage.getWidth()) / 2, (newImage.getHeight() - oldImage.getHeight()) / 2);

Filling pattern changes with object's position. Java

I created a bufferedimage which i applied to a Rectangle to use as filling pattern to shape S. If i change S's position, the filling pattern changes with it instead of remaining "fixed". What could it be?
Image: (the pattern is a 3 stripes, all with the same aspect ratio) :alt text http://img88.imageshack.us/img88/8524/imageby.png
if (bannerPatternCreated == false) {
banner = new BufferedImage(size * 3, size * 3, BufferedImage.TYPE_INT_RGB);
Graphics2D gc = banner.createGraphics();
System.out.println("Creating banner...");
gc.setColor(Color.black);
gc.fillRect(0, 0, size, size * 3);
gc.setColor(Color.BLUE);
gc.fillRect(size, 0, size, size * 3);
gc.setColor(Color.WHITE);
gc.fillRect(size * 2, 0, size, size * 3);
gc.dispose();
bannerPatternCreated = true;
}
Rectangle patternPencil = new Rectangle(size, size);
g2.setPaint(new TexturePaint(banner, patternPencil));
Rectangle recto = new Rectangle(presentX-size, presentY-size, size, size);
g2.fill(recto);

It looks like the texture position is fixed, and so when you move recto around you're just getting a different view of the underlying infinitely-repeating texture.
If you change the patternPencil rect to be the same size/position as recto, I think it should get sorted:
Rectangle patternPencil = new Rectangle(presentX-size, presentY-size, size, size);

I think the TexturePaint docs indicate why the problem:
...the texture is anchored to the
upper left corner of a Rectangle2D
that is specified in user space.
Texture is computed for locations in
the device space by conceptually
replicating the specified Rectangle2D
infinitely in all directions
It's as if you're rectangle is drawn from 0,0 and replicated over and over, and the visible parts are small "windows" that are opened with the call to g2.fill.
If you're drawing to a canvas-type component, could you just use one of the Graphics.drawImage methods at the appropriate x,y?