Using the following example you can capture a snapshot using your camera.. Remember that all the jsr 135
supported mobile devices does not supports for image capture. only few mobiles support for Image capture.
For example nokia 3650 supports this feature.

package SampleImageCapture;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.media.*;
import javax.microedition.media.Control.*;
import javax.microedition.media.control.VideoControl;


public class ImageCaptureMidlet extends MIDlet {

private Display display;
ImageCaptureCanvas canvas;
Player player;
VideoControl videoControl;

public void startApp() {
display = Display.getDisplay(this);
try {
player = Manager.createPlayer("capture://video");
player.realize();
videoControl = (VideoControl) player.getControl("VideoControl");
} catch (Exception e) {
}
canvas = new ImageCaptureCanvas(this, videoControl);
display.setCurrent(canvas);
}

public void pauseApp() {
}

public void destroyApp(boolean unconditional) {
notifyDestroyed();
}
}


package SampleImageCapture;

import javax.microedition.lcdui.*;
import javax.microedition.media.control.VideoControl;
import javax.microedition.media.*;

public class ImageCaptureCanvas extends Canvas {

ImageCaptureMidlet midlet;
VideoControl videoControl;
int width = getWidth();
int height = getHeight();
Player player;
SnapShotCanvas snap;
private Display display;

public ImageCaptureCanvas(ImageCaptureMidlet midlet, VideoControl videoControl) {
this.midlet = midlet;
this.videoControl = videoControl;
this.display = Display.getDisplay(midlet);
videoControl.initDisplayMode(VideoControl.USE_DIRECT_VIDEO, this);
try {
videoControl.setDisplayLocation(2, 2);
videoControl.setDisplaySize(width - 4, height - 4);
} catch (MediaException me) {
try {
videoControl.setDisplayFullScreen(true);
} catch (MediaException me2) {
}
}
videoControl.setVisible(true);
}

public void paint(Graphics g) {
}

protected void keyPressed(int keyCode) {
switch (getGameAction(keyCode)) {
case FIRE:
Thread t = new Thread() {
public void run() {
try {
byte[] raw = videoControl.getSnapshot(null);
Image image = Image.createImage(raw, 0, raw.length);
snap = new SnapShotCanvas(image);
display.setCurrent(snap);
} catch (Exception e) {
}
}
};
t.start();
}
}
}


package SampleImageCapture;

import javax.microedition.lcdui.*;

public class SnapShotCanvas extends Canvas {

private Image image;
public SnapShotCanvas(Image image) {
this.image = image;
setFullScreenMode(true);
}

public void paint(Graphics g) {
g.drawImage(image, getWidth() / 2, getHeight() / 2, Graphics.HCENTER | Graphics.VCENTER);
}
}

link:http://j2mesamples.blogspot.com