Android zxing - 人像摄像头预览/ surfaceview拉伸/扭曲

Question

我已设法使用此处的答案将相机预览旋转为肖像： http ： //code.google.com/p/zxing/issues/detail？id = 178＃c46

然而，预览本身是拉伸/扭曲的 - 高度似乎是拉伸以填充框（但可能是宽度对于屏幕来说太大而且它被压扁以适应）

有没有办法“包装”内容而不是让它拉伸以适应表面视图？

编辑：我通过改变'CameraConfigurationManager'中的'findBestPreviewSizeValue'方法并反转X和Y点（对于下面指针的sean owen！）进行排序，这里是代码：

private static Point findBestPreviewSizeValue(CharSequence previewSizeValueString,
  Point screenResolution) {
int bestX = 0;
int bestY = 0;
int diff = Integer.MAX_VALUE;
for (String previewSize : COMMA_PATTERN.split(previewSizeValueString)) {

  previewSize = previewSize.trim();
  int dimPosition = previewSize.indexOf('x');
  if (dimPosition < 0) {
    Log.w(TAG, "Bad preview-size: " + previewSize);
    continue;
  }

  int newX;
  int newY;
  try {
    newY = Integer.parseInt(previewSize.substring(0, dimPosition));
    newX = Integer.parseInt(previewSize.substring(dimPosition + 1));
    //original:
    //newX = Integer.parseInt(previewSize.substring(0, dimPosition));
    //newY = Integer.parseInt(previewSize.substring(dimPosition + 1));
  } catch (NumberFormatException nfe) {
    Log.w(TAG, "Bad preview-size: " + previewSize);
    continue;
  }

  int newDiff = Math.abs(newX - screenResolution.x) + Math.abs(newY - screenResolution.y);
  if (newDiff == 0) {
    bestX = newY;
    bestY = newX;
    //original:
    //bestX = newX;
    //bestY = newY;
    break;
  } else if (newDiff < diff) {
    bestX = newY;
    bestY = newX;
    //original:
    //bestX = newX;
    //bestY = newY;
    diff = newDiff;
  }

}

if (bestX > 0 && bestY > 0) {
  return new Point(bestX, bestY);
}
return null;
}

Answer 1

除了将预览设置为纵向模式之外，您还需要做更多工作才能使其工作。 例如，您需要选择适当的预览尺寸，因为它是纵向而非横向。

包装肯定不可取吗？ 不，你不能让它包裹; 它总是将整个预览图像投射到SurfaceView ，如果需要可以拉伸。 我想你可以重新实现很多代码来做一些不同的事情，但这会很难。

Answer 2

我有同样的问题但我可以通过反转findBestPreviewSizeValue中CameraConfigurationManager.java文件的宽高比来解决它

 float screenAspectRatio = (float) screenResolution.x / (float) screenResolution.y;

对此

 float screenAspectRatio = (float) screenResolution.y / (float) screenResolution.x;

我在这里找到了解决方案。

http://bighow.net/4660010-Android_zxing___portrait_camera_preview_surfaceview_is_stretched_warped.html

Answer 3

您可以通过此功能获得Priview尺寸：

private List mSupportedPreviewSizes = parameters.getSupportedPreviewSizes（）;

if (mSupportedPreviewSizes != null) {
                mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width, height);
            }

private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
            final double ASPECT_TOLERANCE = 0.1;
            double targetRatio = (double) h / w;

            if (sizes == null)
                return null;

            Camera.Size optimalSize = null;
            double minDiff = Double.MAX_VALUE;

            int targetHeight = h;

            for (Camera.Size size : sizes) {
                double ratio = (double) size.height / size.width;
                if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
                    continue;

                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }

            if (optimalSize == null) {
                minDiff = Double.MAX_VALUE;
                for (Camera.Size size : sizes) {
                    if (Math.abs(size.height - targetHeight) < minDiff) {
                        optimalSize = size;
                        minDiff = Math.abs(size.height - targetHeight);
                    }
                }
            }

            return optimalSize;
        }


            float ratio;
            if (mPreviewSize.height >= mPreviewSize.width)
                ratio = (float) mPreviewSize.height / (float) mPreviewSize.width;
            else
                ratio = (float) mPreviewSize.width / (float) mPreviewSize.height;

            after getting ratio set your size in 

            protected void onMeasure(int widthMeasureSpec, int                              heightMeasureSpec) {

            setMeasuredDimension((int) (width * ratio), height);
            }

Answer 4

我设法通过更改CameraConfigurationManager.java以下代码来实现此CameraConfigurationManager.java ：

float screenAspectRatio = (float) screenResolution.x / (float) screenResolution.y;

至：

float screenAspectRatio = (float) screenResolution.y / (float) screenResolution.x;

和

float aspectRatio = (float) maybeFlippedWidth / (float) maybeFlippedHeight;

至：

float aspectRatio = (float) maybeFlippedHeight / (float) maybeFlippedWidth;

我在这篇文章中做到了这一点： 在Android上的纵向模式中的Zxing Camera

希望这有助于其他人。

Answer 5

变形的原因可能是相机的预览宽高比与显示器的宽高比不匹配。

手机屏幕的最大宽高比为4：3，如2560x1440,1920x1080等。 当您使用parameter.setPreviewSize（width，height）设置相机预览尺寸时，如果height：width的值不等于您的手机屏幕的宽高比，相机的图片将变形以填充屏幕。