Fix to DELF package (#8679)

* First version of working script to download the GLDv2 dataset

* First version of the DEFL package installation script

* First working version of the DELF package installation script

* Fixed feedback from PR review

* Push to Github of changes to the TFRecord data generation script for DELF.

* Merged commit includes the following changes:
315363544  by Andre Araujo:

    Added the generation of TRAIN and VALIDATE splits from the train dataset.

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314676530  by Andre Araujo:

    Updated script to download GLDv2 images for DELF training.

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314101235  by Andre Araujo:

    Added newly created module 'utils' to the copybara script.

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313677085  by Andre Araujo:

    Code migration from TF1 to TF2 for:
    - logging (replaced usage of tf.compat.v1.logging.info)
    - testing directories (replaced usage of tf.compat.v1.test.get_temp_dir())
    - feature/object extraction scripts (replaced usage of tf.compat.v1.train.string_input_producer and tf.compat.v1.train.start_queue_runners with PIL)

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312770828  by Andre Araujo:

    Internal change.

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PiperOrigin-RevId: 315363544

* First version of the updated README of the DELF training instructions

* Added to the README the section describing the generation of the training data

* Added warning about the TFRecord generation time

* Updated the launch of the training

* Minor README update

* Integrated review feedback

* Merged commit includes the following changes:
315971979  by Andre Araujo:

    Performance optimization in generating the TRAIN and VALIDATION splits per label.

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315578370  by Andre Araujo:

    Tiny fix to char limit in extractor.py.

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315546242  by Andre Araujo:

    Script to measure DELG latency.

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315545801  by Andre Araujo:

    Pre-load PCA parameters, if using them when extracting DELF/G features.

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315450392  by Andre Araujo:

    Code migration from TF1 to TF2 for:
    - loading the models using  in extractor.py and detector.py using tf.saved_model.load
    - removed tf.compat.v1.Session for the extractor and detector model usage

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315406342  by Andre Araujo:

    Internal change.

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PiperOrigin-RevId: 315971979

* Merged commit includes the following changes:
316538447  by Andre Araujo:

    Read the number of classes from the GLDv2 dataset metadata.

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316416973  by Andre Araujo:

    Migration of DELF code to TF2:
    - removed tf.compat.v1.test.get_temp_dir() with FLAGS.test_tmpdir
    - removed delf_v1.py and its dependencies
    - removed tf.compat.v1, Session, Graph dependencies from feature_extractor.py, feature_aggregation_extractor.py and aggregation_extraction.py

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PiperOrigin-RevId: 316538447

* Removed reference to delf_v1
Co-authored-by: Andre Araujo <andrearaujo@google.com>

research/delf/delf/__init__.py

@@ -25,7 +25,6 @@ from delf.protos import delf_config_pb2
 from delf.protos import feature_pb2
 from delf.python import box_io
 from delf.python import datum_io
-from delf.python import delf_v1
 from delf.python import feature_aggregation_extractor
 from delf.python import feature_aggregation_similarity
 from delf.python import feature_extractor