[Bug] 图片使用cv2.imread()可以正常读取，在mmcv.imfrombytes()读取为None

[wangqiang-hue]

Prerequisite

• I have searched Issues and Discussions but cannot get the expected help.
• The bug has not been fixed in the latest version(https://github.com/open-mmlab/mmcv).

Environment

OrderedDict([('sys.platform', 'linux'), ('Python', '3.10.6 (main, Mar 10 2023, 10:55:28) [GCC 11.3.0]'), ('CUDA available', False), ('MUSA available', False), ('numpy_random_seed', 2147483648), ('GCC', 'x86_64-linux-gnu-gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0'), ('PyTorch', '2.1.2+cu121'), ('PyTorch compiling details', 'PyTorch built with:\n - GCC 9.3\n - C++ Version: 201703\n - Intel(R) oneAPI Math Kernel Library Version 2022.2-Product Build 20220804 for Intel(R) 64 architecture applications\n - Intel(R) MKL-DNN v3.1.1 (Git Hash 64f6bcbcbab628e96f33a62c3e975f8535a7bde4)\n - OpenMP 201511 (a.k.a. OpenMP 4.5)\n - LAPACK is enabled (usually provided by MKL)\n - NNPACK is enabled\n - CPU capability usage: AVX512\n - Build settings: BLAS_INFO=mkl, BUILD_TYPE=Release, CUDA_VERSION=12.1, CUDNN_VERSION=8.9.2, CXX_COMPILER=/opt/rh/devtoolset-9/root/usr/bin/c++, CXX_FLAGS= -D_GLIBCXX_USE_CXX11_ABI=0 -fabi-version=11 -fvisibility-inlines-hidden -DUSE_PTHREADPOOL -DNDEBUG -DUSE_KINETO -DLIBKINETO_NOROCTRACER -DUSE_FBGEMM -DUSE_QNNPACK -DUSE_PYTORCH_QNNPACK -DUSE_XNNPACK -DSYMBOLICATE_MOBILE_DEBUG_HANDLE -O2 -fPIC -Wall -Wextra -Werror=return-type -Werror=non-virtual-dtor -Werror=bool-operation -Wnarrowing -Wno-missing-field-initializers -Wno-type-limits -Wno-array-bounds -Wno-unknown-pragmas -Wno-unused-parameter -Wno-unused-function -Wno-unused-result -Wno-strict-overflow -Wno-strict-aliasing -Wno-stringop-overflow -Wno-psabi -Wno-error=pedantic -Wno-error=old-style-cast -Wno-invalid-partial-specialization -Wno-unused-private-field -Wno-aligned-allocation-unavailable -Wno-missing-braces -fdiagnostics-color=always -faligned-new -Wno-unused-but-set-variable -Wno-maybe-uninitialized -fno-math-errno -fno-trapping-math -Werror=format -Werror=cast-function-type -Wno-stringop-overflow, LAPACK_INFO=mkl, PERF_WITH_AVX=1, PERF_WITH_AVX2=1, PERF_WITH_AVX512=1, TORCH_DISABLE_GPU_ASSERTS=ON, TORCH_VERSION=2.1.2, USE_CUDA=ON, USE_CUDNN=ON, USE_EXCEPTION_PTR=1, USE_GFLAGS=OFF, USE_GLOG=OFF, USE_MKL=ON, USE_MKLDNN=ON, USE_MPI=OFF, USE_NCCL=1, USE_NNPACK=ON, USE_OPENMP=ON, USE_ROCM=OFF, \n'), ('TorchVision', '0.16.0+cu121'), ('OpenCV', '4.5.5'), ('MMEngine', '0.10.3'), ('MMCV', '2.1.0'), ('MMCV Compiler', 'GCC 9.3'), ('MMCV CUDA Compiler', '12.1')])

Reproduces the problem - code sample

def transform(self, filename) -> Optional[dict]:
results = {}
filename = "/mnt/volumes/cloudmodel-muses/lad/datasets/images/CapsFusion-120M/397794.jpg"
print(self.file_client_args)
print(self.backend_args)
if self.file_client_args is not None:
file_client = fileio.FileClient.infer_client(
self.file_client_args, filename)
img_bytes = file_client.get(filename)
else:
img_bytes = fileio.get(
filename, backend_args=self.backend_args)
print(type(img_bytes))
img = mmcv.imfrombytes(
img_bytes,
flag=self.color_type,
backend=self.imdecode_backend)
print(self.color_type)
print(self.imdecode_backend)
print(img)
results['with_image'] = True
if self.to_float32:
img = img.astype(np.float32)
results['img'] = img
results['img_shape'] = img.shape[:2]
results['ori_shape'] = img.shape[:2]
return results

Reproduces the problem - command or script

python 名字.py

Reproduces the problem - error message

[2024-04-01 10:05:31,154] [INFO] [real_accelerator.py:191:get_accelerator] Setting ds_accelerator to cuda (auto detect)
None
None
<class 'bytes'>
color
cv2
None
Traceback (most recent call last):
File "/mnt/volumes/cloudmodel-muses/lad/datasets/images/CapsFusion-120M/test_image.py", line 55, in
lif.transform("qq")
File "/mnt/volumes/cloudmodel-muses/lad/datasets/images/CapsFusion-120M/test_image.py", line 48, in transform
results['img_shape'] = img.shape[:2]
AttributeError: 'NoneType' object has no attribute 'shape'

Additional information