我正在实施一个简单的眼动仪,它需要快速截屏屏幕上发生的事情,同时从网络摄像头捕捉视频。
事情就是用机器人做的方式,这里提到:https://stackoverflow.com/questions/2475303/java-library-for-capturing-active-window-screenshot 非常慢。
顺便说一句,从网络摄像头检索视频的速度要快得多,并返回字节数组,这个数据处理速度非常快。
有人知道更快的解决方案吗?可以链接到Java的C ++库也可以提供帮助。
谢谢!
更新: 决定切换到OpenCV,现在正在寻找用它制作截图的方法:)
答案 0 :(得分:11)
这是我在我的一个项目中使用的JNA的特定于Windows的版本。
我发现它比Robot
快一个数量级,即使使用本机调用开销也是如此。
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferInt;
import java.awt.image.DataBufferUShort;
import java.awt.image.DirectColorModel;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import com.sun.jna.Native;
import com.sun.jna.platform.win32.W32API;
import com.sun.jna.win32.W32APIOptions;
public class JNAScreenShot {
public static BufferedImage getScreenshot(Rectangle bounds) {
W32API.HDC windowDC = GDI.GetDC(USER.GetDesktopWindow());
W32API.HBITMAP outputBitmap =
GDI.CreateCompatibleBitmap(windowDC,
bounds.width, bounds.height);
try {
W32API.HDC blitDC = GDI.CreateCompatibleDC(windowDC);
try {
W32API.HANDLE oldBitmap =
GDI.SelectObject(blitDC, outputBitmap);
try {
GDI.BitBlt(blitDC,
0, 0, bounds.width, bounds.height,
windowDC,
bounds.x, bounds.y,
GDI32.SRCCOPY);
} finally {
GDI.SelectObject(blitDC, oldBitmap);
}
GDI32.BITMAPINFO bi = new GDI32.BITMAPINFO(40);
bi.bmiHeader.biSize = 40;
boolean ok =
GDI.GetDIBits(blitDC, outputBitmap, 0, bounds.height,
(byte[]) null, bi, GDI32.DIB_RGB_COLORS);
if (ok) {
GDI32.BITMAPINFOHEADER bih = bi.bmiHeader;
bih.biHeight = - Math.abs(bih.biHeight);
bi.bmiHeader.biCompression = 0;
return bufferedImageFromBitmap(blitDC, outputBitmap, bi);
} else {
return null;
}
} finally {
GDI.DeleteObject(blitDC);
}
} finally {
GDI.DeleteObject(outputBitmap);
}
}
private static BufferedImage
bufferedImageFromBitmap(GDI32.HDC blitDC,
GDI32.HBITMAP outputBitmap,
GDI32.BITMAPINFO bi) {
GDI32.BITMAPINFOHEADER bih = bi.bmiHeader;
int height = Math.abs(bih.biHeight);
final ColorModel cm;
final DataBuffer buffer;
final WritableRaster raster;
int strideBits =
(bih.biWidth * bih.biBitCount);
int strideBytesAligned =
(((strideBits - 1) | 0x1F) + 1) >> 3;
final int strideElementsAligned;
switch (bih.biBitCount) {
case 16:
strideElementsAligned = strideBytesAligned / 2;
cm = new DirectColorModel(16, 0x7C00, 0x3E0, 0x1F);
buffer =
new DataBufferUShort(strideElementsAligned * height);
raster =
Raster.createPackedRaster(buffer,
bih.biWidth, height,
strideElementsAligned,
((DirectColorModel) cm).getMasks(),
null);
break;
case 32:
strideElementsAligned = strideBytesAligned / 4;
cm = new DirectColorModel(32, 0xFF0000, 0xFF00, 0xFF);
buffer =
new DataBufferInt(strideElementsAligned * height);
raster =
Raster.createPackedRaster(buffer,
bih.biWidth, height,
strideElementsAligned,
((DirectColorModel) cm).getMasks(),
null);
break;
default:
throw new IllegalArgumentException("Unsupported bit count: " + bih.biBitCount);
}
final boolean ok;
switch (buffer.getDataType()) {
case DataBuffer.TYPE_INT:
{
int[] pixels = ((DataBufferInt) buffer).getData();
ok = GDI.GetDIBits(blitDC, outputBitmap, 0, raster.getHeight(), pixels, bi, 0);
}
break;
case DataBuffer.TYPE_USHORT:
{
short[] pixels = ((DataBufferUShort) buffer).getData();
ok = GDI.GetDIBits(blitDC, outputBitmap, 0, raster.getHeight(), pixels, bi, 0);
}
break;
default:
throw new AssertionError("Unexpected buffer element type: " + buffer.getDataType());
}
if (ok) {
return new BufferedImage(cm, raster, false, null);
} else {
return null;
}
}
private static final User32 USER = User32.INSTANCE;
private static final GDI32 GDI = GDI32.INSTANCE;
}
interface GDI32 extends com.sun.jna.platform.win32.GDI32 {
GDI32 INSTANCE =
(GDI32) Native.loadLibrary(GDI32.class);
boolean BitBlt(HDC hdcDest,
int nXDest,
int nYDest,
int nWidth,
int nHeight,
HDC hdcSrc,
int nXSrc,
int nYSrc,
int dwRop);
HDC GetDC(HWND hWnd);
boolean GetDIBits(HDC dc, HBITMAP bmp, int startScan, int scanLines,
byte[] pixels, BITMAPINFO bi, int usage);
boolean GetDIBits(HDC dc, HBITMAP bmp, int startScan, int scanLines,
short[] pixels, BITMAPINFO bi, int usage);
boolean GetDIBits(HDC dc, HBITMAP bmp, int startScan, int scanLines,
int[] pixels, BITMAPINFO bi, int usage);
int SRCCOPY = 0xCC0020;
}
interface User32 extends com.sun.jna.platform.win32.User32 {
User32 INSTANCE =
(User32) Native.loadLibrary(User32.class,
W32APIOptions.UNICODE_OPTIONS);
HWND GetDesktopWindow();
}
答案 1 :(得分:6)
robot.createScreenCapture(captureSize);
电话大约需要20毫秒。
答案 2 :(得分:0)
可能是您可以使用JMF ..查看Screen Grabber code @ Oracle's site。我认为它可以帮助您解决问题。
答案 3 :(得分:0)
你一定要试试OpenCV
答案 4 :(得分:0)
要捕获全屏。
Robot robot = new Robot();
Rectangle screenRect = new Rectangle(Toolkit.getDefaultToolkit().getScreenSize());
BufferedImage screenFullImage = robot.createScreenCapture(screenRect);
ImageIO.write(screenFullImage, format, new File(destination));
捕获部分屏幕。
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Rectangle rect = new Rectangle(0, 0, screenSize.width / 2, screenSize.height / 2);
Robot robot = new Robot();
BufferedImage screenFullImage = robot.createScreenCapture(rect);
ImageIO.write(screenFullImage, format, new File(destination));
参考:link