CIFAR 10 ExecuTorch model fine-tuning on the Android app #41

IshanAryendu · 2025-07-15T16:41:57Z

In this tutorial, we are trying to fine-tuning a CIFAR 10 model on an Android device using ExecuTorch PTE + PTD combo. This example is an extension of the the CIFAR training example from the official GitHub repository.

…file

…iles in Cifar10ImageExtractor.kt file

…with newest version of ExecuTorch aar

…n the official ExecuTorch repo

jathu · 2025-07-15T21:41:09Z

@IshanAryendu I think we should follow the current pattern of the repo and put this under cifar/android instead of cifar/app

jathu · 2025-07-15T22:16:36Z

cifar/README.md

+
+For the android environment setup, follow these steps:
+
+1. Install Open JDK using: `brew install openjdk@17`


Not everyone will be using macOS. Let's just delegate the instruction to OpenJDK. However, I also think we don't really need to do this — it might be safe to assume Android engineers already know about this (+ the other instructions related to Android in general below)

I'll update this to direct the people to OpenJDK and follow the steps over there to configure their environment

jathu · 2025-07-15T22:19:47Z

cifar/README.md

+7. Export the paths for these to your environment or add them to the `.bashrc` or `.zshrc` files:
+```bash
+# JAVA config
+export JAVA_HOME=/opt/homebrew/opt/openjdk@17/


This is macOS and version specific, we shouldn't include that. We can reduce these steps to:

Ensure the following environment variables are set: `JAVA_HOME`, `ANDROID_NDK`, `ANDROID_SDK`

Better yet we can enforce that in our build scripts ;)

cifar/README.md

larryliu0820 · 2025-07-16T16:48:14Z

cifar/app/src/main/java/com/example/democifar10/MainActivity.kt

+            }
+            return file.absolutePath
+        } catch (e: IOException) {
+            Log.e("AssetCopy", "Error copying asset $assetName: ${e.message}")


Why this tag instead of ExecuTorchApp?

It was there to track if the files are properly copied. I've replaced it with the debugTag.

larryliu0820 · 2025-07-16T16:48:47Z

cifar/app/src/main/java/com/example/democifar10/MainActivity.kt

+            FileOutputStream(file).use { out ->
+                bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)
+            }
+            Log.d("ExecuTorchApp", "Saved image to ${file.absolutePath}")


Can you extract this tag out as a variable? If we need to change it in the future it would be much easier.

The variable debugTag stores the required tag for easier maintenance

larryliu0820 · 2025-07-16T16:49:24Z

cifar/app/src/main/java/com/example/democifar10/MainActivity.kt

+                }
+
+                trainImagesLoaded += imagesToLoad
+                Log.d("Cifar10Loader", "Total training images loaded so far: $trainImagesLoaded")


inconsistent tag

Fixed the inconsistency

larryliu0820

@psiddh can you also take a look?

psiddh · 2025-07-16T17:33:11Z

cifar/README.md

+
+**Note:** We will rename this file to `executorch.aar` and copy it into the `libs` directory of the android app.
+
+## Creation of Android App


Do we really need this step ? The current app layout has all the necessary files & structure. Can we remove this section ? that way it can be less verbose

Made the recommended changes to the README file

jathu · 2025-07-18T16:30:16Z

cifar/android/CifarETTrainingDemo/README.md

+```bash
+$ sh ./scripts/build_android_library.sh
+$ sh ./extension/android/executorch_android/android_test_setup.sh
+$ ls ./extension/android/executorch_android/
+$ cd extension/android
+$ ./gradlew :executorch_android:testDebugUnitTest
+$ ./gradlew :executorch_android:connectedAndroidTest
+```


Do we really need to do this?

I've retained these steps as a sanity check

Sanity check for who/what?

Oh, these are used to run the unit tests and instrumented tests for the newly built modules

We should assume that the tests already pass — we don't run tests for libraries we use. If a user skips these tests, will the training example work? If so, let's remove it

cifar/android/CifarETTrainingDemo/app/src/test/java/com/example/democifar10/ExampleUnitTest.kt

cifar/android/CifarETTrainingDemo/app/src/main/res/xml/data_extraction_rules.xml

cifar/android/CifarETTrainingDemo/app/src/main/res/xml/backup_rules.xml

cifar/android/CifarETTrainingDemo/app/src/main/java/com/example/democifar10/ui/theme/Type.kt

cifar/android/CifarETTrainingDemo/app/src/main/java/com/example/democifar10/ui/theme/Theme.kt

jathu · 2025-07-18T20:00:58Z

cifar/android/CifarETTrainingDemo/app/src/main/res/values/colors.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>


Do we need this?

seems like Android standard

oh maybe it's optional, since strings.xml doesn't have it?

jathu · 2025-07-18T20:03:03Z

cifar/android/CifarETTrainingDemo/README.md

+```bash
+$ sh ./scripts/build_android_library.sh
+$ sh ./extension/android/executorch_android/android_test_setup.sh
+$ ls ./extension/android/executorch_android/
+$ cd extension/android
+$ ./gradlew :executorch_android:testDebugUnitTest
+$ ./gradlew :executorch_android:connectedAndroidTest
+```


We should assume that the tests already pass — we don't run tests for libraries we use. If a user skips these tests, will the training example work? If so, let's remove it

larryliu0820 · 2025-07-18T20:14:38Z

Please address @jathu's comments

…and copy the outputs to the destination.

psiddh · 2025-07-18T22:11:28Z

cifar/android/CifarETTrainingDemo/README.md

+
+## Creation of Android App
+
+1. Start with a clone of this repository and open the project in Android Studio.


Much cleaner now, can add path to gradle file ?

This file: cifar/android/CifarETTrainingDemo/app/build.gradle.kts?

IshanAryendu added 12 commits July 14, 2025 15:13

Initialized project skeleton

bf7de9b

Initialized the app UI in activity_main.xml.

df7e8a7

Added the gradle build configurations

3c4567e

Added the image preprocessing methods in the ImageTransformations.kt …

294b959

…file

Added the image extraction methods to extract files from the binary f…

3ce90d8

…iles in Cifar10ImageExtractor.kt file

Added the main app logic inside the MainActivity.kt file

5849159

Bug fix: Added missing package header in MainActivity.kt file

b58f083

Bug fix: Updated the target SDK version to ver. 35 for compatibility …

0f55c36

…with newest version of ExecuTorch aar

Removed .idea directory from the repository and updated .gitignore

899af7a

Added the README file to the repo

4c623b7

Removed unused code from the MainActivity.kt file

25cf135

Updated the README to include the reference to the CIFAR 10 example i…

b277125

…n the official ExecuTorch repo

meta-cla bot added the CLA Signed This label is managed by the Meta Open Source bot. label Jul 15, 2025

JacobSzwejbka requested review from larryliu0820 and mergennachin July 15, 2025 16:44

psiddh self-requested a review July 15, 2025 16:46

Bug fix: Fixed the filename for the python script in the README

ecfef17

psiddh requested review from kirklandsign, lucylq and shoumikhin July 15, 2025 21:45

jathu reviewed Jul 15, 2025

View reviewed changes

larryliu0820 reviewed Jul 16, 2025

View reviewed changes

psiddh reviewed Jul 16, 2025

View reviewed changes

IshanAryendu added 3 commits July 16, 2025 16:38

Refactored the code to follow current pattern of the repo

6da7b74

Refactored the code to maintain the current structure of the target repo

16cfe3b

Addressed the comments for refactoring the README

efac06d

IshanAryendu added 5 commits July 17, 2025 11:15

Fixed the debug tag in the app

0df0012

Refactored the README file

cef3212

Removed unneeded image files from the repository.

78ecd5a

Fixed the directory structure

d133723

Removed the preexisting files

8f098a9

jathu reviewed Jul 18, 2025

View reviewed changes

Refactored and formatted the code

8ee76fe

jathu reviewed Jul 18, 2025

View reviewed changes

IshanAryendu added 3 commits July 18, 2025 10:46

Added the test cases

ea34603

Clean up: Removed unused theming files from the codebase

c31cf82

Removed the jar file from the repo

fd40868

jathu reviewed Jul 18, 2025

View reviewed changes

larryliu0820 approved these changes Jul 18, 2025

View reviewed changes

IshanAryendu added 2 commits July 18, 2025 13:17

Removed the unused theming files

49c28dc

Refactored REDAME to include commands to generate the relevant files …

9ccc677

…and copy the outputs to the destination.

psiddh reviewed Jul 18, 2025

View reviewed changes

IshanAryendu requested a review from psiddh July 18, 2025 22:23

Included the build config file in the README

69e3247


		For the android environment setup, follow these steps:

		1. Install Open JDK using: `brew install openjdk@17`


		Note: We will rename this file to `executorch.aar` and copy it into the `libs` directory of the android app.

		## Creation of Android App


		## Creation of Android App

		1. Start with a clone of this repository and open the project in Android Studio.

CIFAR 10 ExecuTorch model fine-tuning on the Android app #41

Are you sure you want to change the base?

CIFAR 10 ExecuTorch model fine-tuning on the Android app #41

Uh oh!

Conversation

IshanAryendu commented Jul 15, 2025

Uh oh!

jathu commented Jul 15, 2025

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

larryliu0820 left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

larryliu0820 Jul 18, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

larryliu0820 commented Jul 18, 2025

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Uh oh!

larryliu0820 Jul 18, 2025 •

edited

Loading