如何在将图像上传到 firebase 存储之前减小图像的大小？

Question

我已经制作了一个用于图像和视频共享的社交应用程序。但是，加载图像花费了太多时间。我正在使用滑行库。请告诉我如何减少从图库中拾取的图像的大小而不会有相当大的变化图像质量（如 Instagram 那样），然后将其上传到 firebase 存储。请帮忙！

Answer 1

StorageReference childRef2 = [your firebase storage path]
storageRef.child(UserDetails.username+"profilepic.jpg");
                    Bitmap bmp = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath);
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    bmp.compress(Bitmap.CompressFormat.JPEG, 25, baos);
                    byte[] data = baos.toByteArray();
                    //uploading the image
                    UploadTask uploadTask2 = childRef2.putBytes(data);
                    uploadTask2.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                            Toast.makeText(Profilepic.this, "Upload successful", Toast.LENGTH_LONG).show();
                        }
                    }).addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {
                            Toast.makeText(Profilepic.this, "Upload Failed -> " + e, Toast.LENGTH_LONG).show();
                        }
                    });`

just go ahead and do above steps it will reduce your image size and upload it on firebase it reduce the image size upto 1 to 2 mb like on my experience 4mb file became 304kb .

filepath is and File object of your selected image. :)

Answer 2

I have done the same for uploading image to firebase using bitmap.compress

private void postDataToFirebase() {
        mProgressDialog.setMessage("Posting the Blog to Firebase");
        mProgressDialog.setCancelable(false);

        final String titleValue = mPostTitle.getText().toString();
        final String description = mPostDescription.getText().toString();
        if((!TextUtils.isEmpty(titleValue))&& (!TextUtils.isEmpty(description)) && bitmap != null)
        {
            mProgressDialog.show();
            StorageReference filePath = mStorage.child("Blog_Images").child(imagePathName);
            ByteArrayOutputStream bytes = new ByteArrayOutputStream();
            bitmap.compress(Bitmap.CompressFormat.JPEG, 20, bytes);
            String path = MediaStore.Images.Media.insertImage(PostActivity.this.getContentResolver(), bitmap, imagePathName, null);
            Uri uri = Uri.parse(path);
            filePath.putFile(uri).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                @Override
                public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {

                    Uri downloadUrl = taskSnapshot.getDownloadUrl();

                    DatabaseReference newPost = mDatabaseReference.push();
                    newPost.child("Title").setValue(titleValue);
                    newPost.child("Desc").setValue(description);
                    newPost.child("imageUrl").setValue(downloadUrl.toString());
                    Toast.makeText(PostActivity.this, "Data Posted Successfully to Firebase server", Toast.LENGTH_LONG).show();
                    mProgressDialog.dismiss();
                    Intent intent = new Intent(PostActivity.this, MainActivity.class);
                    startActivity(intent);
                }
            });

        }

    }

bitmap.compress(Bitmap.CompressFormat format, int quality, OutputStream stream)

you can change the quality of the bitmap and compress it.

Answer 3

Here i am using this code to upload compressed image on firebase storeage

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode==RC_PHOTO_PICKER && resultCode==RESULT_OK)
        {
            mProgressBar.setVisibility(ProgressBar.VISIBLE);
            Uri selectedImageUri = data.getData();

            Bitmap bmp = null;
            try {
                bmp = MediaStore.Images.Media.getBitmap(getContentResolver(), selectedImageUri);
            } catch (IOException e) {
                e.printStackTrace();
            }
            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            //here you can choose quality factor in third parameter(ex. i choosen 25) 
            bmp.compress(Bitmap.CompressFormat.JPEG, 25, baos);
            byte[] fileInBytes = baos.toByteArray();

           StorageReference photoref = chatPhotosStorageReference.child(selectedImageUri.getLastPathSegment());

           //here i am uploading
           photoref.putBytes(fileInBytes).addOnSuccessListener(this, new OnSuccessListener<UploadTask.TaskSnapshot>() {
                       public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                                          // When the image has successfully uploaded, we get its download URL
                           mProgressBar.setVisibility(ProgressBar.INVISIBLE);

                           Uri downloadUrl = taskSnapshot.getDownloadUrl();
                           String id = chatRoomDataBaseReference.push().getKey();
                           String time = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(Calendar.getInstance().getTime());

                           // Set the download URL to the message box, so that the user can send it to the database
                           FriendlyMessageModel friendlyMessage = new FriendlyMessageModel(id,null, userId, downloadUrl.toString(),time);
                   chatRoomDataBaseReference.child(id).setValue(friendlyMessage);
                                       }
                   });
        }
    }

Answer 4

Kotlin version

    val userId = FirebaseAuth.getInstance().currentUser!!.uid
    val storageRef = FirebaseStorage.getInstance().getReference("UsersPhotos/${userId}.jpg")

    // compressing image
    val bitmap = MediaStore.Images.Media.getBitmap(contentResolver, imageURI)
    val byteArrayOutputStream = ByteArrayOutputStream()
    bitmap.compress(Bitmap.CompressFormat.JPEG, 25, byteArrayOutputStream)
    val reducedImage: ByteArray = byteArrayOutputStream.toByteArray()

        storageRef.putBytes(reducedImage)
        .addOnSuccessListener {

            Log.i("xxx", "Success uploading Image to Firebase!!!")

            storageRef.downloadUrl.addOnSuccessListener {

                //getting image url
                Log.i("xxx",it.toString())
            
             }.addOnFailureListener {

                        Log.i("xxx", "Error getting image download url")
                    }

        }.addOnFailureListener {

            Log.i("xxx", "Failed uploading image to server")
            
        }