Question

第一：目标是什么？我的Java应用程序应该显示摄像机图片的小预览，并且当用户单击按钮时，应该可以拍摄全分辨率的图片。

我在Windows 8.1上使用webcam-capture-0.3.12.jar 以及具有2个值的分辨率数组[2]

Resolutions[INDEX_PREVIEW_RESOLUTION]:  WebcamResolution.QVGA.getSize()
Resolutions[INDEX_CAMERA_RESOLUTION]:  custom resolution 3264x2448

当我通过getFullResolutionImage（）方法进入Eclipse时，它可以工作。但是当我全速运行相同的代码时，来自摄像机的图像为NULL。

我试图添加wait（5000ms）以便进行上下文切换并让其他线程呼吸。没有成功。

一个细节使我花了很多时间才意识到：关闭（）/打开（）相机并设置所需的分辨率

Camera.setViewSize（Resolutions [INDEX_PREVIEW_RESOLUTION]）;

还不够，我还必须重复声明

Camera.setCustomViewSizes（Resolutions）;

每次我重新打开相机时-这是意外的-为什么？


  public BufferedImage getFullResolutionImage() {
    long stamp;
    BufferedImage image;

    System.out.println("Camera is open " + Camera.isOpen());
    if (Camera.isOpen() == true) {
      System.out.println("close camera before switching from preview to full resolution");
      Camera.close();
    }

    Camera.setCustomViewSizes(Resolutions);
    Camera.setViewSize(Resolutions[INDEX_CAMERA_RESOLUTION]);

    stamp = System.currentTimeMillis();
    Camera.open(false); // synchronous
    System.out.println("Camera.open() took " + (System.currentTimeMillis() - stamp) + "ms");

    stamp = System.currentTimeMillis();
    image = Camera.getImage();
    System.out.println("taking a picture took " + (System.currentTimeMillis() - stamp) + "ms");
    if (image != null)
      System.out.println("image has width/height " + image.getWidth() + " " + image.getHeight());
    else
      System.out.println("IMAGE == NULL");

    Camera.close();
    System.out.println("closed camera to switch back to preview resolution");

    System.out.println("now switch back to preview resolution");
    stamp = System.currentTimeMillis();
    try {
      Camera.setCustomViewSizes(Resolutions);
      Camera.setViewSize(Resolutions[INDEX_PREVIEW_RESOLUTION]);
    } catch (Exception ex) {
      System.out.println("Exception while switching back after " + (System.currentTimeMillis() - stamp) + "ms");
    }
    stamp = System.currentTimeMillis();
    Camera.open(true); // asynchronous
    System.out.println("Camera.open() took " + (System.currentTimeMillis() - stamp) + "ms");

    System.out.println("image has width/height " + image.getWidth() + " " + image.getHeight());
    return image;
  }

逐步执行此代码可获得以下结果：

Camera is open true
close camera before switching from preview to full resolution
Camera.open() took 10190ms
taking a picture took 1218ms
image has width/height 3264 2448
closed camera to switch back to preview resolution
now switch back to preview resolution
Camera.open() took 3584ms
image has width/height 3264 2448

在没有调试器的情况下运行相同的代码会给我

Camera is open true
close camera before switching from preview to full resolution
Camera.open() took 9171ms
taking a picture took 0ms
IMAGE == NULL
closed camera to switch back to preview resolution
now switch back to preview resolution
Camera.open() took 1489ms

我不明白-为什么使用/不使用调试器之间的区别？没有调试器：open（）是如此之慢=：-O MS Windows相机应用程序即使在高分辨率下也能显示流畅的图像流。

我没主意-希望得到任何提示

sarxos网络摄像头：动态切换分辨率

0 个答案: