在Android中从相机捕获时获得较小尺寸的图像

时间:2013-11-01 10:38:55

标签: android image camera

在我的Android应用程序中,当我从相机捕获图像时,我想重新调整它的尺寸。当我从画廊拍摄图像时,我成功地重新调整尺寸。但是当我从相机捕捉时,我失败了。请帮忙

if (requestCode == take_image &&  resultCode == RESULT_OK && null != data) {
    thumbnail = (Bitmap) data.getExtras().get("data");  
    image2 = me1;
    addattachmentsToListView(image2);
}

以下是从sdcard调整图像大小的代码:

if (requestCode == UploadFile && resultCode == RESULT_OK && null != data) {
    Uri selectedImage = data.getData();
    try {

        Bitmap image=(decodeUri(selectedImage));
        addattachmentsToListView(image);
        } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}


private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException {
    BitmapFactory.Options o = new BitmapFactory.Options();
    o.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(
    getContentResolver().openInputStream(selectedImage), null, o);

    final int REQUIRED_SIZE = 200;

    int width_tmp = o.outWidth, height_tmp = o.outHeight;
    int scale = 1;
    while (true) {
        if (width_tmp / 1.5 < REQUIRED_SIZE || height_tmp / 1.5 < REQUIRED_SIZE) {
            break;
        }
        width_tmp /= 4;
        height_tmp /= 4;

        //   width_tmp = 20;
        // height_tmp = 20;
        scale *= 2;
    }

    BitmapFactory.Options o2 = new BitmapFactory.Options();
    o2.inSampleSize = scale;
    return BitmapFactory.decodeStream(
    getContentResolver().openInputStream(selectedImage), null, o2);
}

1 个答案:

答案 0 :(得分:0)

public void onPreviewFrame(byte[] data, Camera camera)中,您可以通过这种方式获得位图:

Bitmap bmp = YUVtoBMP(data, ImageFormat.NV21, YOUR_CAMERA_SIZE);

public Bitmap YUVtoBMP(byte[] data, int format, Camera.Size size)
{
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    YuvImage yuvImage = new YuvImage(data, format, size.width, size.height, null);
    yuvImage.compressToJpeg(new Rect(0, 0, size.width, size.height), 50, out);
    byte[] imageBytes = out.toByteArray();
    Options options = new Options();
    options.inPreferQualityOverSpeed = false;
    Bitmap image = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length, options);

    return image;
}

为了缩放位图,您可以:

Bitmap scaled = Bitmap.createScaledBitmap(bmp, NEW_WIDTH, NEW_HEIGHT, true);

这只是一个提示:从此开始,尝试寻找优化(如果有的话)。