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，它花费了太多时间来加载图像。我正在使用滑动库。请告诉我如何减少从图库中拾取的图像的大小而不会发生相当大的变化在图像质量（如Instagram做），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();
                        }
                    });`

只需继续并执行上述步骤，它将减少您的图像大小并将其上传到firebase上，它将图像大小减小到1到2 MB，就像我的经验4mb文件变成304kb一样。

filepath是所选图像的File对象。 :)

Answer 2

我已经使用bitmap.compress将图像上传到firebase

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格式，int quality，OutputStream流）

您可以更改位图的质量并压缩它。

Answer 3

在这里，我使用此代码上传firebase storeage上的压缩图像

@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);
                                       }
                   });
        }
    }