上传前压缩相机图像

Question

我正在使用此代码（来自www.internetria.com）拍照并上传到服务器：

创建：

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
Uri output = Uri.fromFile(new File(foto));
intent.putExtra(MediaStore.EXTRA_OUTPUT, output);
startActivityForResult(intent, TAKE_PICTURE);

onActivityResult:

ImageView iv = (ImageView) findViewById(R.id.imageView1);
        iv.setImageBitmap(BitmapFactory.decodeFile(foto));

        File file = new File(foto);
        if (file.exists()) {
            UploaderFoto nuevaTarea = new UploaderFoto();
            nuevaTarea.execute(foto);
        }
        else
            Toast.makeText(getApplicationContext(), "No se ha realizado la foto", Toast.LENGTH_SHORT).show();

上传者照片：

ProgressDialog pDialog;
String miFoto = "";

@Override
protected Void doInBackground(String... params) {
    miFoto = params[0];
    try { 
        HttpClient httpclient = new DefaultHttpClient();
        httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
        HttpPost httppost = new HttpPost("http://servidor.com/up.php");
        File file = new File(miFoto);
        MultipartEntity mpEntity = new MultipartEntity();
        ContentBody foto = new FileBody(file, "image/jpeg");
        mpEntity.addPart("fotoUp", foto);
        httppost.setEntity(mpEntity);
        httpclient.execute(httppost);
        httpclient.getConnectionManager().shutdown();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

而且我想压缩图片，因为尺寸太大了。

我不知道如何将bitmap.compress(Bitmap.CompressFormat.JPEG, 70, fos); 添加到我的应用中

Answer 1

请看这里：ByteArrayOutputStream to a FileBody

按照这些思路应该可以工作：

替换

File file = new File(miFoto);
ContentBody foto = new FileBody(file, "image/jpeg");

与

Bitmap bmp = BitmapFactory.decodeFile(miFoto)
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bmp.compress(CompressFormat.JPEG, 70, bos);
InputStream in = new ByteArrayInputStream(bos.toByteArray());
ContentBody foto = new InputStreamBody(in, "image/jpeg", "filename");

如果文件大小仍然是个问题，除了压缩图片之外，您可能还需要缩放图片。

Answer 2

将图像转换为Google WebP format 可以节省大量字节，请参阅以下两篇文章，您还可以在服务器端将 webP 转换为 JPG/PNG/GIF。

Java Wrapper of Google WebP API

How to check out Google WebP library and use it in Android as native library

首先，您需要从 Bitmap 中获取像素。

Bitmap bitmap = BitmapFactory.decodeFile(filePath);

int bytes = bitmap.getByteCount();
ByteBuffer buffer = ByteBuffer.allocate(bytes);
bitmap.copyPixelsToBuffer(buffer);
byte[] pixels = buffer.array();

然后，就可以得到WebP字节数组了。

int stride = bytes / height;
int quality = 100;
byte[] encoded = libwebp.WebPEncodeRGBA(pixels, width, height, stride, quality);

Test.png（大小：106KB） Test.webp(大小：48KB)

Answer 3

使用 okhttp 我这样上传：

MediaType MEDIA_TYPE_PNG
                        = MediaType.parse("image/jpeg");

                //Compress Image
                Bitmap bmp = BitmapFactory.decodeFile(fileToUpload.getAbsolutePath());
                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                bmp.compress(Bitmap.CompressFormat.JPEG, 70, bos);

                RequestBody requestBody = new MultipartBuilder()
                        .type(MultipartBuilder.FORM)
                        .addFormDataPart("photo", fileToUpload.getName(), RequestBody.create(MEDIA_TYPE_PNG, bos.toByteArray()))
                        .build();

                request = new Request.Builder()
                        .url(urlToUploadTo)
                        .post(requestBody)
                        .build();

                try {
                    response = client.newCall(request).execute();
                    if (response != null) {
                        if (response.isSuccessful()) {
                            responseResult = response.body().string();
                        }
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }

Answer 4

看看compressImage()方法：

public class MainActivity extends Activity {

private Uri fileUri;
private ImageView img_forCompress;
public static final int MEDIA_TYPE_IMAGE = 1;
private static final int CAMERA_REQUEST = 1888;
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
private static final String IMAGE_DIRECTORY_NAME = "Ibook";
static File mediaFile;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    img_forCompress = (ImageView) findViewById(R.id.img_forCompress);

    img_forCompress.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

            intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

            // start the image capture Intent
            startActivityForResult(intent,
                    CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
        }
    });

}

public Uri getOutputMediaFileUri(int type) {
    return Uri.fromFile(getOutputMediaFile(type));
}

private static File getOutputMediaFile(int type) {

    // External sdcard location
    File mediaStorageDir = new File(
            Environment
                    .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            IMAGE_DIRECTORY_NAME);

    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            Log.d(IMAGE_DIRECTORY_NAME, "Oops! Failed create "
                    + IMAGE_DIRECTORY_NAME + " directory");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
            Locale.getDefault()).format(new Date());

    if (type == MEDIA_TYPE_IMAGE) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator
                + "IMG_" + timeStamp + ".jpg");
    } else {
        return null;
    }
    Log.e("path", "media file:-" + mediaFile);
    return mediaFile;
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);

    Log.e("path", "" + mediaFile.toString());
    String filename = mediaFile.toString();

    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inPreferredConfig = Bitmap.Config.ARGB_8888;
    Bitmap bitmap = BitmapFactory.decodeFile(filename, options);

    compressImage(bitmap);

}



private void compressImage(Bitmap photo) {
    // TODO Auto-generated method stub
    int imageWidth = photo.getWidth();
    int imageHeight = photo.getHeight();
    long length = mediaFile.length();
    int newHeight = 0;
    int newWidth = 0;

    Toast.makeText(MainActivity.this, "oldwidth="+imageWidth+",oldHeight="+imageHeight,Toast.LENGTH_LONG).show();
    Log.e("Old Image gheight and width---------", imageWidth + "-------"
            + imageHeight + " and Size is -- " + length);
    if (imageHeight > 1500 || imageWidth > 1500) {
        if (imageHeight > imageWidth) {
            Log.e("height is more", "true");
            newHeight = 1200;
            newWidth = (newHeight * imageWidth / imageHeight);
        }
        if (imageWidth > imageHeight) {
            Log.e("width is more", "true");
            newWidth = 1200;
            newHeight = (newWidth * imageHeight / imageWidth);
        }
    }
    Toast.makeText(MainActivity.this, "newwidth="+newWidth+",newHeight="+newHeight,Toast.LENGTH_LONG).show();
    Log.e("new Image gheight and width---------", newHeight + "-------"