Small edit to DELF README (#6704)

* Internal change.

PiperOrigin-RevId: 185564155

* Fix small bug when reading DELF features when file is empty.
A new test is added that catches this bug.

PiperOrigin-RevId: 213839503

* Refactors DELF example code to expose a function to create a DELF feature extractor.

PiperOrigin-RevId: 241492615

* Merged commit includes the following changes:
244073180  by Andre Araujo:

    Internal change

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243646498  by Andre Araujo:

    Detect and save bounding boxes for a list of images.
    A new proto is added, along with auxiliary read/write functions, and tests.

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PiperOrigin-RevId: 244073180

* Merged commit includes the following changes:
244872693  by Andre Araujo:

    Small change.

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244871213  by Andre Araujo:

    Small edit to DELF extractor function.

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244790715  by Andre Araujo:

    internal automated change

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244773146  by Andre Araujo:

    Add option to visualize extracted boxes, and change slightly model input.

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244288992  by Andre Araujo:

    Script to cluster DELF features using K-means.

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244275164  by Andre Araujo:

    Scripts to extract DELF features and boxes from Revisited Oxford/Paris datasets, used in Detect-to-Retrieve paper.

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PiperOrigin-RevId: 244872693

* Merged commit includes the following changes:

PiperOrigin-RevId: 244876167

* Updates instructions to include new released models, instructions for DELF and detector extraction, etc.

* Small fix

* Merged commit includes the following changes:
244909336  by Andre Araujo:

    Update to DELF config example to use latest model.

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PiperOrigin-RevId: 244909336

* Revert "Merged commit includes the following changes:"

This reverts commit f41be9f159330f62846d5d8b3d3d5d55cd1874f4.

* Update delf_config_example model

* Small edits to detection instructions

* Specifying GLB location in README

* Mention D2R code release in progress

research/delf/README.md

@@ -108,6 +108,10 @@ a nice figure showing a detection, as:
 
 ![DetectionExample1](delf/python/examples/detection_example_1.jpg)
 
+### Detect-to-Retrieve
+
+Code release is in progress. Stay tuned!
+
 ## Code overview
 
 DELF/D2R code is located under the `delf` directory. There are two directories