DecodeJpeg

tensorflow C++ API

tensorflow::ops::DecodeJpeg

Decode a JPEG-encoded image to a uint8 tensor.

Summary

The attrchannelsindicates 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 attrratioallows 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.

This op also supports decoding PNGs and non-animated GIFs since the interface is the same, though it is cleaner to usetf.image.decode_image.

Arguments:

• scope: A Scope object
• contents: 0-D. The JPEG-encoded image.

Returns:

• Output: 3-D with shape[height, width, channels].

Optional attributes (seeAttrs):

• channels: Number of color channels for the decoded image.
• ratio: Downscaling ratio.
• fancy_upscaling: If true use a slower but nicer upscaling of the chroma planes (yuv420/422 only).
• try_recover_truncated: If true try to recover an image from truncated input.
• acceptable_fraction: The minimum required fraction of lines before a truncated input is accepted.
• dct_method: 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.)

Constructor

• DecodeJpeg(const ::tensorflow::Scope & scope, ::tensorflow::Input contents, const DecodeJpeg::Attrs & attrs) .

Public attributes

• tensorflow::Output image.

DecodeJpeg block

Source link : https://github.com/EXPNUNI/enuSpaceTensorflow/blob/master/enuSpaceTensorflow/tf_image_ops.cpp

Argument:

• Scope scope : A Scope object (A scope is generated automatically each page. A scope is not connected.)
• contents : connect Input node.
• DecodeJpeg::Attrs attrs : input attrs value. ex) channels_ = 3;ratio_ = 1;fancy_upscaling_ = true;try_recover_truncated_ = false;acceptable_fraction_ = 1.0f;dct_method_ = ;

Return:

• Output image : Output object of DecodeJpeg class object.

Result:

• std::vector(Tensor) product_result : Returned object of executed result by calling session.

Using Method