tf.io.decode_and_crop_jpeg
Decode and Crop a JPEG-encoded image to a uint8 tensor.
tf.io.decode_and_crop_jpeg(
    contents, crop_window, channels=0, ratio=1, fancy_upscaling=True,
    try_recover_truncated=False, acceptable_fraction=1, dct_method='', name=None
)
  The attr channels indicates the desired number of color channels for the decoded image.
Accepted values are:
- 0: Use the number of channels in the JPEG-encoded image.
 - 1: output a grayscale image.
 - 3: output an RGB image.
 
If needed, the JPEG-encoded image is transformed to match the requested number of color channels.
The attr ratio allows downscaling the image by an integer factor during decoding. Allowed values are: 1, 2, 4, and 8. This is much faster than downscaling the image later.
It is equivalent to a combination of decode and crop, but much faster by only decoding partial jpeg image.
| Args | |
|---|---|
 contents  |   A Tensor of type string. 0-D. The JPEG-encoded image.  |  
 crop_window  |   A Tensor of type int32. 1-D. The crop window: [crop_y, crop_x, crop_height, crop_width].  |  
 channels  |   An optional int. Defaults to 0. Number of color channels for the decoded image.  |  
 ratio  |   An optional int. Defaults to 1. Downscaling ratio.  |  
 fancy_upscaling  |   An optional bool. Defaults to True. If true use a slower but nicer upscaling of the chroma planes (yuv420/422 only).  |  
 try_recover_truncated  |   An optional bool. Defaults to False. If true try to recover an image from truncated input.  |  
 acceptable_fraction  |   An optional float. Defaults to 1. The minimum required fraction of lines before a truncated input is accepted.  |  
 dct_method  |   An optional string. Defaults to "". string specifying a hint about the algorithm used for decompression. Defaults to "" which maps to a system-specific default. Currently valid values are ["INTEGER_FAST", "INTEGER_ACCURATE"]. The hint may be ignored (e.g., the internal jpeg library changes to a version that does not have that specific option.)  |  
 name  |  A name for the operation (optional). | 
| Returns | |
|---|---|
 A Tensor of type uint8.  |  
    © 2020 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
    https://www.tensorflow.org/versions/r1.15/api_docs/python/tf/io/decode_and_crop_jpeg