Remove dependency on Exif parsing library. (commons-app#2947)

* Remove dependency on Exif parsing library.

* Fix test.

Author: dbrant

app/build.gradle

@@ -91,8 +91,9 @@ dependencies {
     implementation "androidx.cardview:cardview:1.0.0"
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     implementation "androidx.exifinterface:exifinterface:1.0.0"
-    //metadata extractor
-    implementation 'com.drewnoakes:metadata-extractor:2.11.0'
+
+    //swipe_layout
+    implementation 'com.daimajia.swipelayout:library:1.2.0@aar'
 }
 
 android {

app/src/main/java/fr/free/nrw/commons/filepicker/UploadableFile.java

@@ -1,18 +1,15 @@
 package fr.free.nrw.commons.filepicker;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import androidx.exifinterface.media.ExifInterface;
 import androidx.annotation.Nullable;
 
-import com.drew.imaging.ImageMetadataReader;
-import com.drew.imaging.ImageProcessingException;
-import com.drew.metadata.Metadata;
-import com.drew.metadata.exif.ExifSubIFDDirectory;
-
 import java.io.File;
 import java.io.IOException;
 import java.util.Date;
@@ -125,16 +122,13 @@ private DateTimeWithSource getFileCreatedDateFromCP(Context context) {
      * @return
      */
     private DateTimeWithSource getDateTimeFromExif() {
-        Metadata metadata;
         try {
-            metadata = ImageMetadataReader.readMetadata(file);
-            ExifSubIFDDirectory directory = metadata.getFirstDirectoryOfType(ExifSubIFDDirectory.class);
-            if (directory!=null && directory.containsTag(ExifSubIFDDirectory.TAG_DATETIME_ORIGINAL)) {
-                Date date = directory.getDate(ExifSubIFDDirectory.TAG_DATETIME_ORIGINAL);
+            ExifInterface exif = new ExifInterface(file.getAbsolutePath());
+            @SuppressLint("RestrictedApi") long dateTime = exif.getDateTime();
+            if (dateTime != -1) {
+                Date date = new Date(dateTime);
                 return new DateTimeWithSource(date, DateTimeWithSource.EXIF_SOURCE);
             }
-        } catch (ImageProcessingException e) {
-            e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }

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

@@ -1,60 +1,36 @@
 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 androidx.exifinterface.media.ExifInterface;
 
 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) */
-
+ * We try to minimize uploads from the Commons app that might be copyright violations.
+ * If an image does not have any Exif metadata, then it was likely downloaded from the internet,
+ * and is probably not an original work by the user. We detect these kinds of images by looking
+ * for the presence of some basic Exif metadata.
+ */
 @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);
-                }
+            ExifInterface exif = new ExifInterface(path);
+            if (exif.getAttribute(ExifInterface.TAG_MAKE) != null
+                    || exif.getAttribute(ExifInterface.TAG_DATETIME) != null) {
+                return Single.just(ImageUtils.IMAGE_OK);
             }
+        } catch (Exception e) {
+            return Single.just(ImageUtils.FILE_NO_EXIF);
         }
         return Single.just(ImageUtils.FILE_NO_EXIF);
     }
-
 }
 

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

@@ -1,12 +1,9 @@
 package fr.free.nrw.commons.upload;
 
 import android.content.Context;
-import android.net.Uri;
 
 import org.apache.commons.lang3.StringUtils;
 
-import java.io.IOException;
-
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
@@ -23,10 +20,7 @@
 
 /**
  * Methods for pre-processing images to be uploaded
- *//*if (dataInBytes[0] == 70 && dataInBytes[1] == 66 && dataInBytes[2] == 77 && dataInBytes[3] == 68) {
-                Timber.d("Contains FBMD");
-                return Single.just(ImageUtils.FILE_FBMD);
-            }*/
+ */
 @Singleton
 public class ImageProcessingService {
     private final FileUtilsWrapper fileUtilsWrapper;
@@ -64,12 +58,11 @@ Single<Integer> validateImage(UploadModel.UploadItem uploadItem, boolean checkTi
         }
         Timber.d("Checking the validity of image");
         String filePath = uploadItem.getMediaUri().getPath();
-        Uri contentUri=uploadItem.getContentUri();
         Single<Integer> duplicateImage = checkDuplicateImage(filePath);
         Single<Integer> wrongGeoLocation = checkImageGeoLocation(uploadItem.getPlace(), filePath);
         Single<Integer> darkImage = checkDarkImage(filePath);
         Single<Integer> itemTitle = checkTitle ? validateItemTitle(uploadItem) : Single.just(ImageUtils.IMAGE_OK);
-        Single<Integer> checkFBMD = checkFBMD(context,contentUri);
+        Single<Integer> checkFBMD = checkFBMD(filePath);
         Single<Integer> checkEXIF = checkEXIF(filePath);
 
         Single<Integer> zipResult = Single.zip(duplicateImage, wrongGeoLocation, darkImage, itemTitle,
@@ -84,31 +77,21 @@ Single<Integer> validateImage(UploadModel.UploadItem uploadItem, boolean checkTi
     }
 
     /**
-     * Other than the Image quality we need to check that using this Image doesn't violate's facebook's copyright's.
-     * Whenever a user tries to upload an image that was downloaded from Facebook then we warn the user with a message to stop the upload
-     * To know whether the Image is downloaded from facebook:
-     * -We read the metadata of any Image and check for FBMD
-     * -Facebook downloaded image's contains metadata of the type IPTC
-     * - From this IPTC metadata we extract a byte array that contains FBMD as it's initials. If the image was downloaded from facebook
-     * Thus we successfully protect common's from Facebook's copyright violation
+     * We want to discourage users from uploading images to Commons that were taken from Facebook.
+     * This attempts to detect whether an image was downloaded from Facebook by heuristically
+     * searching for metadata that is specific to images that come from Facebook.
      */
-
-    public Single<Integer> checkFBMD(Context context,Uri contentUri) {
-        try {
-            return readFBMD.processMetadata(context,contentUri);
-        } catch (IOException e) {
-            return Single.just(ImageUtils.FILE_FBMD);
-        }
+    private Single<Integer> checkFBMD(String filepath) {
+        return readFBMD.processMetadata(filepath);
     }
 
     /**
-    * 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){
+     * We try to minimize uploads from the Commons app that might be copyright violations.
+     * If an image does not have any Exif metadata, then it was likely downloaded from the internet,
+     * and is probably not an original work by the user. We detect these kinds of images by looking
+     * for the presence of some basic Exif metadata.
+     */
+    private Single<Integer> checkEXIF(String filepath) {
         return EXIFReader.processMetadata(filepath);
     }
 

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

@@ -1,14 +1,6 @@
 package fr.free.nrw.commons.upload;
 
-import android.content.Context;
-import android.net.Uri;
-
-import com.drew.imaging.ImageMetadataReader;
-import com.drew.imaging.ImageProcessingException;
-import com.drew.metadata.Metadata;
-import com.drew.metadata.Tag;
-import com.drew.metadata.iptc.IptcDirectory;
-
+import java.io.FileInputStream;
 import java.io.IOException;
 
 import javax.inject.Inject;
@@ -17,37 +9,38 @@
 import fr.free.nrw.commons.utils.ImageUtils;
 import io.reactivex.Single;
 
+/**
+ * We want to discourage users from uploading images to Commons that were taken from Facebook.
+ * This attempts to detect whether an image was downloaded from Facebook by heuristically
+ * searching for metadata that is specific to images that come from Facebook.
+ */
 @Singleton
 public class ReadFBMD {
 
     @Inject
     public ReadFBMD() {
-
     }
 
-    public Single<Integer> processMetadata(Context context, Uri contentUri) throws IOException {
-        Metadata readMetadata = null;
+    public Single<Integer> processMetadata(String path) {
         try {
-            readMetadata = ImageMetadataReader.readMetadata(context.getContentResolver().openInputStream(contentUri));
-        } catch (ImageProcessingException e) {
-            e.printStackTrace();
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
+            int psBlockOffset;
+            int fbmdOffset;
+
+            try (FileInputStream fs = new FileInputStream(path)) {
+                byte[] bytes = new byte[4096];
+                fs.read(bytes);
+                fs.close();
+                String fileStr = new String(bytes);
+                psBlockOffset = fileStr.indexOf("8BIM");
+                fbmdOffset = fileStr.indexOf("FBMD");
+            }
 
-        IptcDirectory iptcDirectory = readMetadata != null ? readMetadata.getFirstDirectoryOfType(IptcDirectory.class) : null;
-        if (iptcDirectory == null) {
-            return Single.just(ImageUtils.IMAGE_OK);
-        }
-        /**
-         * We parse through all the tags in the IPTC directory  if the tagname equals "Special Instructions".
-         * And the description string starts with FBMD.
-         * Then the source of image is facebook
-         * */
-        for (Tag tag : iptcDirectory.getTags()) {
-            if (tag.getTagName().equals("Special Instructions") && tag.getDescription().substring(0, 4).equals("FBMD")) {
+            if (psBlockOffset > 0 && fbmdOffset > 0
+                    && fbmdOffset > psBlockOffset && fbmdOffset - psBlockOffset < 0x80) {
                 return Single.just(ImageUtils.FILE_FBMD);
             }
+        } catch (IOException e) {
+            e.printStackTrace();
         }
         return Single.just(ImageUtils.IMAGE_OK);
     }