Overview. Java2D. Graphics in Java2D: Colour Images Fonts. The bigger picture of Java Graphics: Java Advanced Imaging (JAI) API Java3D

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Graphics in Java2D: Colour Images Fonts Overview The bigger picture of Java Graphics: Java Advanced Imaging (JAI) API Java3D The bigger picture of Java multimedia ITNP80: Multimedia 1 ITNP80:

1 Graphics in Java2D: Colour Images Fonts Overview The bigger picture of Java Graphics: Java Advanced Imaging (JAI) API Java3D The bigger picture of Java multimedia ITNP80: Multimedia 1 ITNP80: Multimedia 2 Java2D Java 2D extends the basic AWT graphics facilities A brief overview: Draw lines of any thickness Fill shapes with gradients and textures Move, rotate, scale, and shear text and graphics Composite overlapping text and graphics Filters, enabling simple image operations, e.g. blurring sharpening ITNP80: Multimedia 3 ITNP80: Multimedia 4

2 Colour Models In Java2D, the java.awt.color package provides colours (class ColorSpace) All the common colour spaces are provided, including standard RGB (red-green-blue) greyscale colour models CMY, CMYK (cyan-magenta-yellow-black) HSV (hue-saturation-value) CIE XYZ CIE Lab, and more! Typical usage: (alpha,red,green,blue) is stored as an int in the RGB colour model (class ColorModel) Image Types Image in java.awt abstract superclass of all classes for representing images ImageIcon class provided by Swing, for using as icons implements Icon BufferedImage direct subclass of Image in java.awt.image pixel data available for manipulation ITNP80: Multimedia 5 ITNP80: Multimedia 6 Buffered Images Painting Components public void paintcomponent(graphics g) { Graphics2D g2d = (Graphics2D) g; g2d.setcolor(color.red); g2d.drawrect(100,100,60,40); } Raster object Array of pixel values ColorModel object Methods 15! 10! Create a 2D graphics context to use Java2D A graphics context (g & g2d) holds contextual information (like a colour, as above) for doing drawing operations. bufferedim.getrgb(15,10) ITNP80: Multimedia 7 ITNP80: Multimedia 8

Painting Buffered Images A buffered image has its own 2D graphics context Drawing to a buffered image does not appear on the screen Stroke setstroke Graphics2D State Clip setclip Graphics2D g2 =

drawrect(100,100,60,40); 2D graphics context (g2d) can hold a large variety of state information Paint setpaint Composite setcomposite Transform settransform Font setfont RenderingHints

3 Painting Buffered Images A buffered image has its own 2D graphics context Drawing to a buffered image does not appear on the screen Stroke setstroke Graphics2D State Clip setclip Graphics2D g2 = bufferedim.creategraphics(); g2.setcolor(color.red); g2.drawrect(100,100,60,40); 2D graphics context (g2d) can hold a large variety of state information Paint setpaint Composite setcomposite Transform settransform Font setfont RenderingHints setrenderinghints ITNP80: Multimedia 9 ITNP80: Multimedia 10 Shapes and Painting Stroking public void paint(graphics g) { Graphics2D g2d = (Graphics2D) g; g2d.setcolor(color.magenta); BasicStroke stroke = new BasicStroke(2.0f); g2d.setstroke(stroke); g2d.draw(new Rectangle2D.Double(40,40,60,40)); g2.drawrect(100,100,60,40); } BasicStroke widestroke = new BasicStroke(8.0f); g2d.setstroke(widestroke); g2d.draw(new RoundRectangle2D.Double(40,120,60,40, 10, 10)); ITNP80: Multimedia 11 ITNP80: Multimedia 12

Transformations (affine) Example: Rotation Rotation Translating

13 ITNP80: Multimedia 14 Example (Rotation) AffineTransform at = new

filloval(200,200,50,30); Compositing When two bitmap images overlap, a

colours): overlaying transparency XOR // rotate 60 degrees about point

settransform(at); g2d.setcolor(color.green); g2d.

.. XOR applies an XOR operation to the pixel values bit-by-bit.

4 Transformations (affine) Example: Rotation Rotation Translating (moving) Reflection Shearing (stretching) Scaling ITNP80: Multimedia 13 ITNP80: Multimedia 14 Example (Rotation) AffineTransform at = new AffineTransform(); g2d.settransform(at); g2d.setcolor(color.red); g2d.filloval(200,200,50,30); Compositing When two bitmap images overlap, a compositing rule may be applied (pixel-by-pixel calculation of colours): overlaying transparency XOR // rotate 60 degrees about point (180.0,180.0) at.rotate(math.pi/3.0,180.0,180.0); g2d.settransform(at); g2d.setcolor(color.green); g2d.filloval(200,200,50,30);... XOR applies an XOR operation to the pixel values bit-by-bit. A convenient property of XOR is: (Colour1 XOR Colour2) XOR Colour2 = Colour1 (so applying the operation twice gets us back to the original) ITNP80: Multimedia 15 ITNP80: Multimedia 16

Compositing Rules in Java2D Compositing Rule: XOR g2d.setcolor(color.black); g2d.fillrect(0,0,200,120); Various! 8 different rules altogether g2d.setcolor(color.red); g2d.

setcolor(color.white); g2d.fillrect(10,50,180,20);!

5 Compositing Rules in Java2D Compositing Rule: XOR g2d.setcolor(color.black); g2d.fillrect(0,0,200,120); Various! 8 different rules altogether g2d.setcolor(color.red); g2d.filloval(20,40,40,40); g2d.setcolor(color.green); g2d.filloval(80,40,40,40); g2d.setcolor(color.blue); g2d.filloval(140,40,40,40); g2d.setxormode(color.black); g2d.setcolor(color.white); g2d.fillrect(10,50,180,20);! ITNP80: Multimedia 17 ITNP80: Multimedia 18 Rendering Hints Rendering hints are not guaranteed to be obeyed Various available, including dithering anti-aliasing The Java2D Graphics Pipeline Graphic Primitive Transformation Rasterizer Clipping Painting Compositing Rule ITNP80: Multimedia 19 ITNP80: Multimedia 20

6 Java Advanced Imaging (JAI) JAI Extends features provided in the Java2D API, in the area of image input, manipulation and output javax.media.jai and various javax.media.jai.xxx Not part of the standard J2SDK installation Greater range of file formats (for input/output) GIF (Compuserve s Graphics Interchange Format) JPEG (a way of compressing images from the Joint Photographics Experts Group) PNG (Portable Network Graphics) TIF (Tag Image File Format) BMP (Microsoft s bitmap format) PNM (Portably any Map format - includes PBM,PGM,PPM) FPX (FlashPix) Greater range of colour models ColorSpaceJAI extends ColorSpace Conversion methods between different colour spaces are also provided ColorSpaces provided include RGB, non-colour-corrected RGB, Grayscale, CMY/CMYK CIE XYZ, Lab Lab, HSV, a luminance (γ)/chrominance (colour) standard for Kodak PhotoCD images ITNP80: Multimedia 21 ITNP80: Multimedia 22 JAI JAI More ways to model images than just BufferedImage, e.g. Tiled Images (TiledImage) Image Collections (AttributedImageCollection) Multi-resolution Images (MultiResolutionRenderableImage) Many, many methods for image manipulation, e.g. Combining (compositing) two images in various ways Image enhancement, e.g. Sharpening Blurring Transformations - additionally... Methods for extracting data from images, e.g. finding the frequency of occurrence of colours in images finding the edges (or outlines) in an image other statistical operations on the pixel data ITNP80: Multimedia 23 ITNP80: Multimedia 24

7 Perspective and Java3D Warping ITNP80: Multimedia 25 ITNP80: Multimedia 26 Java Media APIs Java2D Java Advanced Imaging (JAI) Java3D Java Media Framework audio, video, time-based media Java Sound audio, midi Java Speech speech technology including digital recognition, speech synthesisers only 3rd party implementations Further information: End of Lecture ITNP80: Multimedia 27 ITNP80: Multimedia 28

public void paintcomponent(graphics g) { Graphics2D g2 = (Graphics2D)g;... }

public void paintcomponent(graphics g) { Graphics2D g2 = (Graphics2D)g;... } 6.1 RANDERING The original JDK 1.0 had a very simple mechanism for drawing shapes. You select color and paint mode, and call methods of the Graphics class such as drawrect or filloval. The Java 2D API