Using eval() for Decode JPEG
danleh93 opened this issue · 6 comments
tensorflow/models/slim/preprocessing/inception_preprocessing
I modified the preprocess_for_eval(...) function to look like:
def preprocess_for_eval(img, height, width,
central_fraction=0.875, scope=None):
image = tf.image.convert_image_dtype(tf.image.decode_jpeg(img, channels=3), dtype=tf.float32)
with tf.name_scope(scope, 'eval_image', [image, height, width]):
if image.dtype != tf.float32:
image = tf.image.convert_image_dtype(image, dtype=tf.float32)
# Crop the central region of the image with an area containing 87.5% of
# the original image.
if central_fraction:
image = tf.image.central_crop(image, central_fraction=central_fraction)
if height and width:
# Resize the image to the specified height and width.
image = tf.expand_dims(image, 0)
image = tf.image.resize_bilinear(image, [height, width],
align_corners=False)
image = tf.squeeze(image, [0])
image = tf.sub(image, 0.5)
image = tf.mul(image, 2.0)
return image
The code executes perfectly, however, when I do something like
image_tensor = preprocess_for_eval("path/to/image.jpeg",300,300).eval(session=sess)
I get an error stating:
Traceback (most recent call last):
File "preprocess_for_eval.py", line 53, in <module>
print(image.eval())
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 564, in eval
return _eval_using_default_session(self, feed_dict, self.graph, session)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 3784, in _eval_using_default_session
return session.run(tensors, feed_dict)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 717, in run
run_metadata_ptr)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 915, in _run
feed_dict_string, options, run_metadata)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 965, in _do_run
target_list, options, run_metadata)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 985, in _do_call
raise type(e)(node_def, op, message)
tensorflow.python.framework.errors.InvalidArgumentError: Invalid JPEG data, size 52
[[Node: DecodeJpeg = DecodeJpeg[acceptable_fraction=1, channels=3, fancy_upscaling=true, ratio=1, try_recover_truncated=false, _device="/job:localhost/replica:0/task:0/cpu:0"](DecodeJpeg/contents)]]
Caused by op u'DecodeJpeg', defined at:
File "preprocess_for_eval.py", line 50, in <module>
image = preprocess_for_eval('/home/ec2-user/workspace/results/flowers/daisy2.jpeg', 300,300)
File "preprocess_for_eval.py", line 29, in preprocess_for_eval
image = tf.image.convert_image_dtype(tf.image.decode_jpeg(img, channels=3), dtype=tf.float32)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/ops/gen_image_ops.py", line 283, in decode_jpeg
name=name)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/framework/op_def_library.py", line 748, in apply_op
op_def=op_def)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 2403, in create_op
original_op=self._default_original_op, op_def=op_def)
File "/usr/local/lib/python2.7/site-packages/tensorflow/python/framework/ops.py", line 1305, in __init__
self._traceback = _extract_stack()
InvalidArgumentError (see above for traceback): Invalid JPEG data, size 52
[[Node: DecodeJpeg = DecodeJpeg[acceptable_fraction=1, channels=3, fancy_upscaling=true, ratio=1, try_recover_truncated=false, _device="/job:localhost/replica:0/task:0/cpu:0"](DecodeJpeg/contents)]]
I know for a fact that my image is a JPEG because when I do:
file image.jpeg on the command line I get:
JPEG image data, JFIF standard 1.01, resolution (DPI), density 72x72, segment length 16, baseline, precision 8, 300x300, frames 3
Even when I try tf.image.decode_png I get an invalid PNG header message.
@danleh93 : It is possible that the image is not valid (at 52-bytes, it seems really small :)
Note that file image.jpeg is just reading the header, so it is possible that the image file's content was truncated making it an invalid jpeg but still keeping the small header intact enough for file to think that it is an image.
Does the image load up correctly in an image viewer? You can also try the identify tool to see if it is really a valid image.
Let us know what you find.
Thanks.
@asimshankar : Thanks for the response. I did some further investigation: The image does, in fact, load up correctly in an image viewer. Furthermore, when running identify -verbose image.jpeg the resulting output is:
Format: JPEG (Joint Photographic Experts Group JFIF format)
Class: DirectClass
Geometry: 300x300+0+0
Resolution: 72x72
Print size: 4.16667x4.16667
Units: PixelsPerInch
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Red:
min: 76 (0.298039)
max: 255 (1)
mean: 249.772 (0.979499)
standard deviation: 17.1539 (0.0672703)
kurtosis: 21.3926
skewness: -4.31776
Green:
min: 55 (0.215686)
max: 255 (1)
mean: 249.395 (0.978019)
standard deviation: 19.7617 (0.077497)
kurtosis: 26.8176
skewness: -4.87254
Blue:
min: 0 (0)
max: 255 (1)
mean: 246.014 (0.964762)
standard deviation: 33.5775 (0.131676)
kurtosis: 33.2542
skewness: -5.51364
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 248.394 (0.974093)
standard deviation: 24.578 (0.0963842)
kurtosis: 46.7875
skewness: -6.14705
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Interlace: None
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Compose: Over
Page geometry: 300x300+0+0
Dispose: Undefined
Iterations: 0
Compression: JPEG
Quality: 90
Orientation: Undefined
Properties:
date:create: 2016-10-19T17:28:35+00:00
date:modify: 2016-10-19T17:28:35+00:00
jpeg:colorspace: 2
jpeg:sampling-factor: 2x2,1x1,1x1
signature: 40b91d70c11d16b555bc242d95343424f6f79a10b11350c392b4291730d8a304
Artifacts:
filename: image.jpeg
verbose: true
Tainted: False
Filesize: 6.77KB
Number pixels: 90K
Pixels per second: 0B
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick 6.7.8-9 2016-06-22 Q16 http://www.imagemagick.org
I am not sure why Tensorflow is only reading it as 52-bytes. When I do a ls -l image.jpeg the result is about 6.7KB.
Oh, wait, sorry, I missed something.
You're passing the filename to tf.decode_jpeg, which is not what it takes. It takes a string tensor that is the contents of the file. See https://www.tensorflow.org/api_docs/python/image.html#decode_jpeg
So the 52-bytes is the filename.
Instead you want something like this:
contents = ''
with open('path/to/image.jpeg') as f:
contents = f.read()
tf.image.decode_jpeg(contents)Hope that helps.
That worked! Can't believe I forgot about that part. Thanks so much!
Hi~, I meet a problem about convert_image_dtype.
with open('/home/give/Documents/dataset/ADEChallengeData2016/images/validation/ADE_val_00000001.jpg') as f:
content = f.read()
image = tf.image.decode_jpeg(content, channels=3)
image_float = tf.image.convert_image_dtype(image, dtype=tf.float32)
img, img_float = sess.run([image, image_float])
# print img
# print img_float
print np.max(img_float), np.min(img_float)when i execute this code, why np.max(img_float), np.min(img_float) both are nan? The value of img is normal. Do you know the reason? Thanks