[pytorch] Adds image classification resnet18 base model to model zoo (d…

…eepjavalibrary#2079)

api/src/main/java/ai/djl/modality/cv/translator/ImageFeatureExtractor.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance
+ * with the License. A copy of the License is located at
+ *
+ * http://aws.amazon.com/apache2.0/
+ *
+ * or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES
+ * OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ */
+package ai.djl.modality.cv.translator;
+
+import ai.djl.ndarray.NDList;
+import ai.djl.translate.TranslatorContext;
+
+import java.util.Map;
+
+/**
+ * A generic {@link ai.djl.translate.Translator} for Image Classification feature extraction tasks.
+ */
+public class ImageFeatureExtractor extends BaseImageTranslator<byte[]> {
+
+    /**
+     * Constructs an Image Classification using {@link Builder}.
+     *
+     * @param builder the data to build with
+     */
+    ImageFeatureExtractor(Builder builder) {
+        super(builder);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public byte[] processOutput(TranslatorContext ctx, NDList list) {
+        return list.get(0).toByteArray();
+    }
+
+    /**
+     * Creates a builder to build a {@code ImageFeatureExtractor}.
+     *
+     * @return a new builder
+     */
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    /**
+     * Creates a builder to build a {@code ImageFeatureExtractor} with specified arguments.
+     *
+     * @param arguments arguments to specify builder options
+     * @return a new builder
+     */
+    public static Builder builder(Map<String, ?> arguments) {
+        Builder builder = new Builder();
+        builder.configPreProcess(arguments);
+        return builder;
+    }
+
+    /** A Builder to construct a {@code ImageFeatureExtractor}. */
+    public static class Builder extends BaseBuilder<Builder> {
+
+        Builder() {}
+
+        /** {@inheritDoc} */
+        @Override
+        protected Builder self() {
+            return this;
+        }
+
+        /**
+         * Builds the {@link ImageFeatureExtractor} with the provided data.
+         *
+         * @return an {@link ImageFeatureExtractor}
+         */
+        public ImageFeatureExtractor build() {
+            validate();
+            return new ImageFeatureExtractor(this);
+        }
+    }
+}

api/src/main/java/ai/djl/modality/cv/translator/ImageFeatureExtractorFactory.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance
+ * with the License. A copy of the License is located at
+ *
+ * http://aws.amazon.com/apache2.0/
+ *
+ * or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES
+ * OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions
+ * and limitations under the License.
+ */
+package ai.djl.modality.cv.translator;
+
+import ai.djl.Model;
+import ai.djl.modality.Input;
+import ai.djl.modality.Output;
+import ai.djl.modality.cv.Image;
+import ai.djl.modality.cv.translator.wrapper.FileTranslator;
+import ai.djl.modality.cv.translator.wrapper.InputStreamTranslator;
+import ai.djl.modality.cv.translator.wrapper.UrlTranslator;
+import ai.djl.translate.Translator;
+import ai.djl.translate.TranslatorFactory;
+import ai.djl.util.Pair;
+
+import java.io.InputStream;
+import java.lang.reflect.Type;
+import java.net.URL;
+import java.nio.file.Path;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/** A {@link TranslatorFactory} that creates an {@link ImageClassificationTranslator}. */
+public class ImageFeatureExtractorFactory implements TranslatorFactory {
+
+    private static final Set<Pair<Type, Type>> SUPPORTED_TYPES = new HashSet<>();
+
+    static {
+        SUPPORTED_TYPES.add(new Pair<>(Image.class, byte[].class));
+        SUPPORTED_TYPES.add(new Pair<>(Path.class, byte[].class));
+        SUPPORTED_TYPES.add(new Pair<>(URL.class, byte[].class));
+        SUPPORTED_TYPES.add(new Pair<>(InputStream.class, byte[].class));
+        SUPPORTED_TYPES.add(new Pair<>(Input.class, Output.class));
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public Set<Pair<Type, Type>> getSupportedTypes() {
+        return SUPPORTED_TYPES;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    @SuppressWarnings("unchecked")
+    public <I, O> Translator<I, O> newInstance(
+            Class<I> input, Class<O> output, Model model, Map<String, ?> arguments) {
+        ImageFeatureExtractor translator = ImageFeatureExtractor.builder(arguments).build();
+        if (input == Image.class && output == byte[].class) {
+            return (Translator<I, O>) translator;
+        } else if (input == Path.class && output == byte[].class) {
+            return (Translator<I, O>) new FileTranslator<>(translator);
+        } else if (input == URL.class && output == byte[].class) {
+            return (Translator<I, O>) new UrlTranslator<>(translator);
+        } else if (input == InputStream.class && output == byte[].class) {
+            return (Translator<I, O>) new InputStreamTranslator<>(translator);
+        } else if (input == Input.class && output == Output.class) {
+            return (Translator<I, O>) new ImageServingTranslator(translator);
+        }
+        throw new IllegalArgumentException("Unsupported input/output types.");
+    }
+}

engines/pytorch/pytorch-model-zoo/src/main/java/ai/djl/pytorch/zoo/PtModelZoo.java

@@ -33,6 +33,8 @@ public class PtModelZoo extends ModelZoo {
 
     PtModelZoo() {
         addModel(REPOSITORY.model(CV.IMAGE_CLASSIFICATION, GROUP_ID, "resnet", "0.0.1"));
+        addModel(
+                REPOSITORY.model(CV.IMAGE_CLASSIFICATION, GROUP_ID, "resnet18_embedding", "0.0.1"));
         addModel(REPOSITORY.model(CV.OBJECT_DETECTION, GROUP_ID, "ssd", "0.0.1"));
         addModel(REPOSITORY.model(NLP.QUESTION_ANSWER, GROUP_ID, "bertqa", "0.0.1"));
         addModel(REPOSITORY.model(NLP.SENTIMENT_ANALYSIS, GROUP_ID, "distilbert", "0.0.1"));

engines/pytorch/pytorch-model-zoo/src/test/resources/mlrepo/model/cv/image_classification/ai/djl/pytorch/resnet18_embedding/metadata.json

@@ -0,0 +1,42 @@
+{
+  "metadataVersion": "0.1",
+  "resourceType": "model",
+  "application": "cv/image_classification",
+  "groupId": "ai.djl.pytorch",
+  "artifactId": "resnet18_embedding",
+  "name": "resnet18_embedding",
+  "description": "A pretrained resnet18 model as an embedding base model",
+  "website": "http://www.djl.ai/engines/pytorch/model-zoo",
+  "licenses": {
+    "license": {
+      "name": "The Apache License, Version 2.0",
+      "url": "https://www.apache.org/licenses/LICENSE-2.0"
+    }
+  },
+  "artifacts": [
+    {
+      "version": "0.0.1",
+      "snapshot": false,
+      "name": "resnet18_embedding",
+      "arguments": {
+        "width": 224,
+        "height": 224,
+        "resize": 256,
+        "centerCrop": true,
+        "normalize": true,
+        "translatorFactory": "ai.djl.modality.cv.translator.ImageFeatureExtractorFactory"
+      },
+      "options": {
+        "mapLocation": "true"
+      },
+      "files": {
+        "model": {
+          "uri": "0.0.1/resnet18_embedding.zip",
+          "name": "",
+          "sha1Hash": "e37db339e87dc13ae0831e45818fca454f526ffb",
+          "size": 41574720
+        }
+      }
+    }
+  ]
+}