Provide utility methods to capture image in specific format

closes #15

webcam-capture-examples/webcam-capture-manycams/src/main/java/com/github/sarxos/webcam/ManyCamerasAtOnceExample.java

@@ -7,8 +7,6 @@
 import javax.swing.JFrame;
 import javax.swing.SwingUtilities;
 
-import com.github.sarxos.webcam.ds.buildin.WebcamDefaultDevice;
-
 
 @SuppressWarnings("serial")
 public class ManyCamerasAtOnceExample extends JFrame {
@@ -21,7 +19,7 @@ public ManyCamerasAtOnceExample() {
 
 		for (Webcam webcam : Webcam.getWebcams()) {
 
-			webcam.setViewSize(WebcamDefaultDevice.SIZE_QVGA);
+			webcam.setViewSize(WebcamResolution.QVGA.getSize());
 			WebcamPanel panel = new WebcamPanel(webcam, false);
 
 			panels.add(panel);

webcam-capture-examples/webcam-capture-qrcode/src/main/java/com/github/sarxos/webcam/WebcamQRCodeExample.java

@@ -1,5 +1,6 @@
 package com.github.sarxos.webcam;
 
+import java.awt.Dimension;
 import java.awt.FlowLayout;
 import java.awt.image.BufferedImage;
 import java.util.concurrent.Executor;
@@ -9,7 +10,6 @@
 import javax.swing.JFrame;
 import javax.swing.JTextArea;
 
-import com.github.sarxos.webcam.ds.buildin.WebcamDefaultDevice;
 import com.google.zxing.BinaryBitmap;
 import com.google.zxing.LuminanceSource;
 import com.google.zxing.MultiFormatReader;
@@ -36,15 +36,17 @@ public WebcamQRCodeExample() {
 		setTitle("Read QR / Bar Code With Webcam");
 		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
+		Dimension size = WebcamResolution.QVGA.getSize();
+
 		webcam = Webcam.getWebcams().get(0);
-		webcam.setViewSize(WebcamDefaultDevice.SIZE_QVGA);
+		webcam.setViewSize(size);
 
 		panel = new WebcamPanel(webcam);
-		panel.setPreferredSize(WebcamDefaultDevice.SIZE_QVGA);
+		panel.setPreferredSize(size);
 
 		textarea = new JTextArea();
 		textarea.setEditable(false);
-		textarea.setPreferredSize(WebcamDefaultDevice.SIZE_QVGA);
+		textarea.setPreferredSize(size);
 
 		add(panel);
 		add(textarea);

webcam-capture/src/example/java/com/github/sarxos/webcam/DifferentFileFormatsExample.java

@@ -0,0 +1,54 @@
+package com.github.sarxos.webcam;
+
+import java.nio.ByteBuffer;
+
+import com.github.sarxos.webcam.util.ImageUtils;
+
+
+public class DifferentFileFormatsExample {
+
+	public static void main(String[] args) {
+
+		Webcam webcam = Webcam.getDefault();
+
+		// save files directly to disk
+
+		// creates test1.bmp
+		WebcamUtils.capture(webcam, "test1", ImageUtils.FORMAT_BMP);
+		// creates test1.gif
+		WebcamUtils.capture(webcam, "test1", ImageUtils.FORMAT_GIF);
+		// creates test1.jpg
+		WebcamUtils.capture(webcam, "test1", ImageUtils.FORMAT_JPG);
+		// creates test1.png
+		WebcamUtils.capture(webcam, "test1", ImageUtils.FORMAT_PNG);
+		// creates test1.wbmp
+		WebcamUtils.capture(webcam, "test1", ImageUtils.FORMAT_WBMP);
+
+		// this is equivalent of this code
+
+		// creates test2.bmp
+		WebcamUtils.capture(webcam, "test2", "bmp");
+		// creates test2.gif
+		WebcamUtils.capture(webcam, "test2", "gif");
+		// creates test2.jpg
+		WebcamUtils.capture(webcam, "test2", "jpg");
+		// creates test2.png
+		WebcamUtils.capture(webcam, "test2", "png");
+		// creates test2.wbmp
+		WebcamUtils.capture(webcam, "test2", "wbmp");
+
+		// NOTE !!!
+		// you can use any format you want until there is a ImageIO plugin
+		// installed which supports it
+
+		// get image as bytes array / bytes buffer
+
+		// save image in JPG format and return as array of bytes
+		byte[] bytes = WebcamUtils.getImageBytes(webcam, "jpg");
+		System.out.println("Bytes length: " + bytes.length);
+
+		// save image in JPG format and return as byte buffer
+		ByteBuffer buffer = WebcamUtils.getImageByteBuffer(webcam, "jpg");
+		System.out.println("Buffer length: " + buffer.capacity());
+	}
+}

webcam-capture/src/main/java/com/github/sarxos/webcam/WebcamResolution.java

@@ -0,0 +1,31 @@
+package com.github.sarxos.webcam;
+
+import java.awt.Dimension;
+
+
+public enum WebcamResolution {
+
+	QQVGA(176, 144),
+	QVGA(320, 240),
+	CIF(352, 288),
+	HVGA(480, 400),
+	VGA(640, 480),
+	PAL(768, 576),
+	SVGA(800, 600),
+	XGA(1024, 768),
+	HD720(1280, 720),
+	WXGA(1280, 768),
+	SXGA(1280, 1024),
+	UXGA(1600, 1200),
+	QXGA(2048, 1536);
+
+	private Dimension size = null;
+
+	private WebcamResolution(int width, int height) {
+		this.size = new Dimension(width, height);
+	}
+
+	public Dimension getSize() {
+		return size;
+	}
+}

webcam-capture/src/main/java/com/github/sarxos/webcam/WebcamUtils.java

@@ -2,22 +2,52 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.ByteBuffer;
 
 import javax.imageio.ImageIO;
 
+import com.github.sarxos.webcam.util.ImageUtils;
+
 
 public class WebcamUtils {
 
 	public static final void capture(Webcam webcam, File file) {
 		try {
-			ImageIO.write(webcam.getImage(), "PNG", file);
+			ImageIO.write(webcam.getImage(), ImageUtils.FORMAT_JPG, file);
 		} catch (IOException e) {
-			e.printStackTrace();
+			throw new WebcamException(e);
+		}
+	}
+
+	public static final void capture(Webcam webcam, File file, String format) {
+		try {
+			ImageIO.write(webcam.getImage(), format, file);
+		} catch (IOException e) {
+			throw new WebcamException(e);
 		}
 	}
 
 	public static final void capture(Webcam webcam, String filename) {
-		capture(webcam, new File(filename + ".png"));
+		if (filename.endsWith(".jpg")) {
+			filename = filename + ".jpg";
+		}
+		capture(webcam, new File(filename));
+	}
+
+	public static final void capture(Webcam webcam, String filename, String format) {
+		String ext = "." + format.toLowerCase();
+		if (!filename.startsWith(ext)) {
+			filename = filename + ext;
+		}
+		capture(webcam, new File(filename), format);
+	}
+
+	public static final byte[] getImageBytes(Webcam webcam, String format) {
+		return ImageUtils.toByteArray(webcam.getImage(), format);
+	}
+
+	public static final ByteBuffer getImageByteBuffer(Webcam webcam, String format) {
+		return ByteBuffer.wrap(getImageBytes(webcam, format));
 	}
 
 }

webcam-capture/src/main/java/com/github/sarxos/webcam/ds/buildin/WebcamDefaultDevice.java

@@ -17,6 +17,7 @@
 
 import com.github.sarxos.webcam.WebcamDevice;
 import com.github.sarxos.webcam.WebcamException;
+import com.github.sarxos.webcam.WebcamResolution;
 import com.github.sarxos.webcam.ds.buildin.cgt.CloseSessionTask;
 import com.github.sarxos.webcam.ds.buildin.cgt.GetImageTask;
 import com.github.sarxos.webcam.ds.buildin.cgt.GetSizeTask;
@@ -33,20 +34,6 @@ public class WebcamDefaultDevice implements WebcamDevice {
 		}
 	}
 
-	public static final Dimension SIZE_QQVGA = new Dimension(176, 144);
-	public static final Dimension SIZE_QVGA = new Dimension(320, 240);
-	public static final Dimension SIZE_CIF = new Dimension(352, 288);
-	public static final Dimension SIZE_HVGA = new Dimension(480, 400);
-	public static final Dimension SIZE_VGA = new Dimension(640, 480);
-	public static final Dimension SIZE_PAL = new Dimension(768, 576);
-	public static final Dimension SIZE_SVGA = new Dimension(800, 600);
-	public static final Dimension SIZE_XGA = new Dimension(1024, 768);
-	public static final Dimension SIZE_HD720 = new Dimension(1280, 720);
-	public static final Dimension SIZE_WXGA = new Dimension(1280, 768);
-	public static final Dimension SIZE_SXGA = new Dimension(1280, 1024);
-	public static final Dimension SIZE_UXGA = new Dimension(1600, 1200);
-	public static final Dimension SIZE_QXGA = new Dimension(2048, 1536);
-
 	/**
 	 * Logger.
 	 */
@@ -58,12 +45,12 @@ public class WebcamDefaultDevice implements WebcamDevice {
 	 */
 	// @formatter:off
 	private final static Dimension[] DIMENSIONS = new Dimension[] {
-		SIZE_QQVGA,
-		SIZE_QVGA,
-		SIZE_CIF,
-		SIZE_HVGA,
-		SIZE_VGA,
-		SIZE_XGA,
+		WebcamResolution.QQVGA.getSize(),
+		WebcamResolution.QVGA.getSize(),
+		WebcamResolution.CIF.getSize(),
+		WebcamResolution.HVGA.getSize(),
+		WebcamResolution.VGA.getSize(),
+		WebcamResolution.XGA.getSize(),
 	};
 	// @formatter:on
 

webcam-capture/src/main/java/com/github/sarxos/webcam/util/ImageUtils.java

@@ -2,10 +2,41 @@
 
 import java.awt.Graphics2D;
 import java.awt.image.BufferedImage;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+import javax.imageio.ImageIO;
+
+import com.github.sarxos.webcam.WebcamException;
 
 
 public class ImageUtils {
 
+	/**
+	 * Graphics Interchange Format.
+	 */
+	public static final String FORMAT_GIF = "GIF";
+
+	/**
+	 * Portable Network Graphic format.
+	 */
+	public static final String FORMAT_PNG = "PNG";
+
+	/**
+	 * Joint Photographic Experts Group format.
+	 */
+	public static final String FORMAT_JPG = "JPG";
+
+	/**
+	 * Bitmap image format.
+	 */
+	public static final String FORMAT_BMP = "BMP";
+
+	/**
+	 * Wireless Application Protocol Bitmap image format.
+	 */
+	public static final String FORMAT_WBMP = "WBMP";
+
 	public static BufferedImage premultiple(BufferedImage src) {
 		BufferedImage pre = new BufferedImage(512, 512, BufferedImage.TYPE_INT_ARGB_PRE);
 		Graphics2D g2 = pre.createGraphics();
@@ -24,4 +55,31 @@ public static BufferedImage unpremultiple(BufferedImage pre) {
 		return src;
 	}
 
+	/**
+	 * Convert {@link BufferedImage} to byte array.
+	 * 
+	 * @param image the image to be converted
+	 * @param format the output image format
+	 * @return New array of bytes
+	 */
+	public static byte[] toByteArray(BufferedImage image, String format) {
+
+		byte[] bytes = null;
+		ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+		try {
+			ImageIO.write(image, format, baos);
+			bytes = baos.toByteArray();
+		} catch (IOException e) {
+			throw new WebcamException(e);
+		} finally {
+			try {
+				baos.close();
+			} catch (IOException e) {
+				throw new WebcamException(e);
+			}
+		}
+
+		return bytes;
+	}
 }