Fixes #97: Added metadata reader for reading exif data (#2581)

* initial commit

* initial commit

* reading 3 exif directories

* minor changes

* fixed unit tests

* reviwied requested changes

* minor changes

* minor changes

app/src/main/java/fr/free/nrw/commons/upload/EXIFReader.java

@@ -0,0 +1,60 @@
+package fr.free.nrw.commons.upload;
+
+import com.drew.imaging.ImageMetadataReader;
+import com.drew.imaging.ImageProcessingException;
+import com.drew.metadata.Directory;
+import com.drew.metadata.Metadata;
+
+import java.io.File;
+import java.io.IOException;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import fr.free.nrw.commons.utils.ImageUtils;
+import io.reactivex.Single;
+import timber.log.Timber;
+
+/**
+* We try to avoid copyright violations in commons app.
+* For doing that we read EXIF data using the library metadata-reader
+* If an image doesn't have any EXIF Directoris in it's metadata then the image is an
+* internet download image(and not the one taken using phone's camera) */
+
+@Singleton
+public class EXIFReader {
+    @Inject
+    public EXIFReader() {
+        //Empty
+    }
+    /**
+    * The method takes in path of the image and reads metadata using the library metadata-extractor
+     * And the checks for the presence of EXIF Directories in metadata object
+     * */
+
+    public Single<Integer> processMetadata(String path) {
+        Metadata readMetadata = null;
+        try {
+            readMetadata = ImageMetadataReader.readMetadata(new File(path));
+        } catch (ImageProcessingException e) {
+            Timber.d(e.toString());
+        } catch (IOException e) {
+            Timber.d(e.toString());
+        }
+        if (readMetadata != null) {
+            for (Directory directory : readMetadata.getDirectories()) {
+                // In case of internet downloaded image these three fields are not present
+                if (directory.getName().equals("Exif IFD0") //Contains information about the device capturing the photo
+                        || directory.getName().equals("Exif SubIFD") //contains information like date, time and pixels of the image
+                        || directory.getName().equals("Exif Thumbnail")) //contains information about image thumbnail like compression and reolution
+                {
+                    Timber.d(directory.getName() + " Contains metadata");
+                    return Single.just(ImageUtils.IMAGE_OK);
+                }
+            }
+        }
+        return Single.just(ImageUtils.FILE_NO_EXIF);
+    }
+
+}
+

app/src/main/java/fr/free/nrw/commons/upload/ImageProcessingService.java

@@ -34,17 +34,19 @@ public class ImageProcessingService {
     private final ImageUtilsWrapper imageUtilsWrapper;
     private final MediaWikiApi mwApi;
     private final ReadFBMD readFBMD;
+    private final EXIFReader EXIFReader;
 
     @Inject
     public ImageProcessingService(FileUtilsWrapper fileUtilsWrapper,
                                   BitmapRegionDecoderWrapper bitmapRegionDecoderWrapper,
                                   ImageUtilsWrapper imageUtilsWrapper,
-                                  MediaWikiApi mwApi, ReadFBMD readFBMD) {
+                                  MediaWikiApi mwApi, ReadFBMD readFBMD, EXIFReader EXIFReader) {
         this.fileUtilsWrapper = fileUtilsWrapper;
         this.bitmapRegionDecoderWrapper = bitmapRegionDecoderWrapper;
         this.imageUtilsWrapper = imageUtilsWrapper;
         this.mwApi = mwApi;
         this.readFBMD = readFBMD;
+        this.EXIFReader = EXIFReader;
     }
 
     /**
@@ -69,16 +71,15 @@ public class ImageProcessingService {
         Single<Integer> darkImage = checkDarkImage(filePath);
         Single<Integer> itemTitle = checkTitle ? validateItemTitle(uploadItem) : Single.just(ImageUtils.IMAGE_OK);
         Single<Integer> checkFBMD = checkFBMD(context,contentUri);
-
+        Single<Integer> checkEXIF = checkEXIF(filePath);
         Single<Integer> zipResult = Single.zip(duplicateImage, wrongGeoLocation, darkImage, itemTitle,
                 (duplicate, wrongGeo, dark, title) -> {
                     Timber.d("Result for duplicate: %d, geo: %d, dark: %d, title: %d", duplicate, wrongGeo, dark, title);
                     return duplicate | wrongGeo | dark | title;
                 });
-
-        return Single.zip(zipResult, checkFBMD, (zip, fbmd) -> {
-            Timber.d("zip:" + zip + "fbmd:" + fbmd);
-            return zip | fbmd;
+        return Single.zip(zipResult, checkFBMD , checkEXIF , (zip , fbmd , exif)->{
+            Timber.d("zip:" + zip + "fbmd:" + fbmd + "exif:" + exif);
+            return zip | fbmd | exif;
                 });
     }
 
@@ -100,6 +101,17 @@ public class ImageProcessingService {
         }
     }
 
+    /**
+    * To avoid copyright we check for EXIF data in any image.
+     * Images that are downloaded from internet generally don't have any EXIF data in them
+     * while images taken via camera or screenshots in phone have EXIF data with them.
+     * So we check if the image has no EXIF data then we display a warning to the user
+     * * */
+
+    public Single<Integer> checkEXIF(String filepath){
+        return EXIFReader.processMetadata(filepath);
+    }
+
 
     /**
      * Checks item title

app/src/main/java/fr/free/nrw/commons/utils/ImageUtils.java

@@ -55,7 +55,11 @@ public class ImageUtils {
      * ie. 10000
      */
     public static final int FILE_FBMD = 1 << 4;
-
+    /**
+    * The parameter FILE_NO_EXIF is returned from the class EXIFReader if the uploaded image does not contains EXIF data else returns IMAGE_OK
+    * ie. 100000
+    */
+    public static final int FILE_NO_EXIF = 1 << 5;
     public static final int IMAGE_OK = 0;
     public static final int IMAGE_KEEP = -1;
     public static final int IMAGE_WAIT = -2;

app/src/test/kotlin/fr/free/nrw/commons/upload/ImageProcessingServiceTest.kt

@@ -30,6 +30,8 @@ class u {
     internal var mwApi: MediaWikiApi? = null
     @Mock
     internal var readFBMD: ReadFBMD?=null
+    @Mock
+    internal var readEXIF: EXIFReader?=null
 
     @InjectMocks
     var imageProcessingService: ImageProcessingService? = null
@@ -84,6 +86,8 @@ class u {
                 .thenReturn(false)
         `when`(readFBMD?.processMetadata(ArgumentMatchers.any(),ArgumentMatchers.any()))
                 .thenReturn(Single.just(ImageUtils.IMAGE_OK))
+        `when`(readEXIF?.processMetadata(ArgumentMatchers.anyString()))
+                .thenReturn(Single.just(ImageUtils.IMAGE_OK))
     }
 
     @Test