Android：使用固定纵横比的相机拍摄图像后裁剪图像

Question

我正在尝试拍摄后裁剪图像，我的代码如下：

   private void doTakePhotoAction() {

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        intent.putExtra(MediaStore.EXTRA_OUTPUT, MediaStore.Images.Media.EXTERNAL_CONTENT_URI.toString());
        intent.putExtra("crop", "true");
        intent.putExtra("aspectX", 1);
        intent.putExtra("aspectY", 1);
        intent.putExtra("outputX", 96);
        intent.putExtra("outputY", 96);

        try {
            intent.putExtra("return-data", true);
            startActivityForResult(intent, PICK_FROM_CAMERA);
        } catch (ActivityNotFoundException e) {
            //Do nothing for now
        }
    }

使用上面的代码，我可以进入裁剪模式，裁剪图片。但是，不强制使用 1:1 纵横比，也不是 outputX 和 outputY。我相信这是因为目的是拍照，而不是裁剪。我还编写了另一种方法从 Intent 中获取 getData()，然后使用以下方法：

Intent intent = new Intent("com.android.camera.action.CROP");
intent.setClassName("com.android.camera", "com.android.camera.CropImage");

但是，当我这样做时，我收到以下运行时错误：

E/AndroidRuntime(14648): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.camera/com.android.camera.CropImage}: java.lang.NullPointerException

感谢您的帮助！ :)

Answer 1

读了一些之后，我意识到不能这么简单。我修改后的通讯录源在http://github.com/Wysie，有兴趣的可以看看。此外，这是我为使其正常工作所做的工作：

private void doTakePhotoAction() {
    // http://2009.hfoss.org/Tutorial:Camera_and_Gallery_Demo
    // http://stackoverflow.com/questions/1050297/how-to-get-the-url-of-the-captured-image
    // http://www.damonkohler.com/2009/02/android-recipes.html
    // http://www.firstclown.us/tag/android/
    // The one I used to get everything working: http://groups.google.com/group/android-developers/msg/2ab62c12ee99ba30 

    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

    //Wysie_Soh: Create path for temp file
    mImageCaptureUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(),
                        "tmp_contact_" + String.valueOf(System.currentTimeMillis()) + ".jpg"));

    intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);

    try {
        intent.putExtra("return-data", true);
        startActivityForResult(intent, PICK_FROM_CAMERA);
    } catch (ActivityNotFoundException e) {
        //Do nothing for now
    }
}

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode != RESULT_OK) {
        return;
    }

    switch (requestCode) {

    case CROP_FROM_CAMERA: {
        //Wysie_Soh: After a picture is taken, it will go to PICK_FROM_CAMERA, which will then come here
        //after the image is cropped.

        final Bundle extras = data.getExtras();

        if (extras != null) {
            Bitmap photo = extras.getParcelable("data");

            mPhoto = photo;
            mPhotoChanged = true;
            mPhotoImageView.setImageBitmap(photo);
            setPhotoPresent(true);
        }

        //Wysie_Soh: Delete the temporary file                        
        File f = new File(mImageCaptureUri.getPath());            
        if (f.exists()) {
            f.delete();
        }

        InputMethodManager mgr = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        mgr.showSoftInput(mPhotoImageView, InputMethodManager.SHOW_IMPLICIT);

        break;
    }

    case PICK_FROM_CAMERA: {
        //Wysie_Soh: After an image is taken and saved to the location of mImageCaptureUri, come here
        //and load the crop editor, with the necessary parameters (96x96, 1:1 ratio)

        Intent intent = new Intent("com.android.camera.action.CROP");
        intent.setClassName("com.android.camera", "com.android.camera.CropImage");

        intent.setData(mImageCaptureUri);
        intent.putExtra("outputX", 96);
        intent.putExtra("outputY", 96);
        intent.putExtra("aspectX", 1);
        intent.putExtra("aspectY", 1);
        intent.putExtra("scale", true);
        intent.putExtra("return-data", true);            
        startActivityForResult(intent, CROP_FROM_CAMERA);

        break;

    }
    }
}

希望对你有帮助:)

Answer 2

看看这篇文章。我在我的 android 1.5 (Htc Magic) 上对其进行了测试，并且运行良好。

Android Works

Answer 3

你试过这个Intent（但保留你已经拥有的crop/aspect/output/return-data extras）吗？

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");

这基本上就是Android contacts application 所做的，所以它可能不太适合您的用例（即立即拍照，而不是从图库中选择一张或一张新照片）。

无论如何都值得一试！ :)

Answer 4

虽然这可能是一个非常古老的线程，但我可以使用以下代码以编程方式裁剪图片：

        btnTakePicture.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            Intent cameraIntent = new Intent(
                    android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

            startActivityForResult(cameraIntent, CAMERA_REQUEST);
        }
    });

然后我将其裁剪为：

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {

        photo = (Bitmap) data.getExtras().get("data");

        performcrop();
    }

}

private void performcrop() {
    DisplayMetrics displayMetrics = this.getResources().getDisplayMetrics();
    int width = displayMetrics.widthPixels;
    int height = displayMetrics.heightPixels;

    Bitmap croppedBmp = Bitmap.createBitmap(photo, 0, 0, width / 2,
            photo.getHeight());

    imageTaken.setImageBitmap(croppedBmp);
}

imageTaken 在我看来是一个 ImageView 组件。可以看我的源码Here