extract and apply the image orientation from exif data in imageToPdf (#2073)

src/main/java/stirling/software/SPDF/utils/ImageProcessingUtils.java

@@ -1,30 +1,46 @@
 package stirling.software.SPDF.utils;
 
+import java.awt.geom.AffineTransform;
+import java.awt.image.AffineTransformOp;
 import java.awt.image.BufferedImage;
 import java.awt.image.DataBuffer;
 import java.awt.image.DataBufferByte;
 import java.awt.image.DataBufferInt;
+import java.io.IOException;
+import java.io.InputStream;
 import java.nio.ByteBuffer;
 
+import javax.imageio.ImageIO;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.multipart.MultipartFile;
+
+import com.drew.imaging.ImageMetadataReader;
+import com.drew.imaging.ImageProcessingException;
+import com.drew.metadata.Metadata;
+import com.drew.metadata.MetadataException;
+import com.drew.metadata.exif.ExifSubIFDDirectory;
+
 public class ImageProcessingUtils {
 
+    private static final Logger logger = LoggerFactory.getLogger(PdfUtils.class);
+
     static BufferedImage convertColorType(BufferedImage sourceImage, String colorType) {
         BufferedImage convertedImage;
         switch (colorType) {
             case "greyscale":
-                convertedImage =
-                        new BufferedImage(
-                                sourceImage.getWidth(),
-                                sourceImage.getHeight(),
-                                BufferedImage.TYPE_BYTE_GRAY);
+                convertedImage = new BufferedImage(
+                        sourceImage.getWidth(),
+                        sourceImage.getHeight(),
+                        BufferedImage.TYPE_BYTE_GRAY);
                 convertedImage.getGraphics().drawImage(sourceImage, 0, 0, null);
                 break;
             case "blackwhite":
-                convertedImage =
-                        new BufferedImage(
-                                sourceImage.getWidth(),
-                                sourceImage.getHeight(),
-                                BufferedImage.TYPE_BYTE_BINARY);
+                convertedImage = new BufferedImage(
+                        sourceImage.getWidth(),
+                        sourceImage.getHeight(),
+                        BufferedImage.TYPE_BYTE_BINARY);
                 convertedImage.getGraphics().drawImage(sourceImage, 0, 0, null);
                 break;
             default: // full color
@@ -59,4 +75,49 @@ public class ImageProcessingUtils {
             return data;
         }
     }
+
+    public static double extractImageOrientation(InputStream is) throws IOException {
+        try {
+            Metadata metadata = ImageMetadataReader.readMetadata(is);
+            ExifSubIFDDirectory directory = metadata.getFirstDirectoryOfType(ExifSubIFDDirectory.class);
+            if (directory == null) {
+                return 0;
+            }
+            int orientationTag = directory.getInt(ExifSubIFDDirectory.TAG_ORIENTATION);
+            switch (orientationTag) {
+                case 1:
+                    return 0;
+                case 6:
+                    return 90;
+                case 3:
+                    return 180;
+                case 8:
+                    return 270;
+                default:
+                    logger.warn("Unknown orientation tag: {}", orientationTag);
+                    return 0;
+            }
+        } catch (ImageProcessingException | MetadataException e) {
+            return 0;
+        }
+    }
+
+    public static BufferedImage applyOrientation(BufferedImage image, double orientation) {
+        if (orientation == 0) {
+            return image;
+        }
+        AffineTransform transform = AffineTransform.getRotateInstance(
+                Math.toRadians(orientation),
+                image.getWidth() / 2.0,
+                image.getHeight() / 2.0);
+        AffineTransformOp op = new AffineTransformOp(transform, AffineTransformOp.TYPE_BILINEAR);
+        return op.filter(image, null);
+    }
+
+    public static BufferedImage loadImageWithExifOrientation(MultipartFile file)
+            throws IOException {
+        BufferedImage image = ImageIO.read(file.getInputStream());
+        double orientation = extractImageOrientation(file.getInputStream());
+        return applyOrientation(image, orientation);
+    }
 }

src/main/java/stirling/software/SPDF/utils/PdfUtils.java

@@ -194,7 +194,8 @@ public class PdfUtils {
 
         pdfDocument.close();
 
-        // Assumes the expectedPageSize is in the format "widthxheight", e.g. "595x842" for A4
+        // Assumes the expectedPageSize is in the format "widthxheight", e.g. "595x842"
+        // for A4
         String[] dimensions = expectedPageSize.split("x");
         float expectedPageWidth = Float.parseFloat(dimensions[0]);
         float expectedPageHeight = Float.parseFloat(dimensions[1]);
@@ -407,7 +408,7 @@ public class PdfUtils {
                         addImageToDocument(doc, pdImage, fitOption, autoRotate);
                     }
                 } else {
-                    BufferedImage image = ImageIO.read(file.getInputStream());
+                    BufferedImage image = ImageProcessingUtils.loadImageWithExifOrientation(file);
                     BufferedImage convertedImage =
                             ImageProcessingUtils.convertColorType(image, colorType);
                     // Use JPEGFactory if it's JPEG since JPEG is lossy