Add support for EXIF rotation tag in images
authorNiki Roo <niki@nikiroo.be>
Sat, 2 Apr 2016 10:33:46 +0000 (12:33 +0200)
committerNiki Roo <niki@nikiroo.be>
Sat, 2 Apr 2016 10:33:46 +0000 (12:33 +0200)
src/be/nikiroo/jvcard/resources/StringUtils.java

index 1772bdfdb19582bd729cdc63e946e54d9a2705f9..a838af93e3dbff9cd33f7e9dd695459d94483bf7 100644 (file)
@@ -1,6 +1,8 @@
 package be.nikiroo.jvcard.resources;
 
 import java.awt.Image;
+import java.awt.geom.AffineTransform;
+import java.awt.image.AffineTransformOp;
 import java.awt.image.BufferedImage;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -254,9 +256,77 @@ public class StringUtils {
         *             in case of IO error
         */
        static public BufferedImage toImage(String b64data) throws IOException {
-               BufferedImage image = ImageIO.read(new ByteArrayInputStream(
-                               DatatypeConverter.parseBase64Binary(b64data)));
-               image.toString();
+               ByteArrayInputStream in = new ByteArrayInputStream(
+                               DatatypeConverter.parseBase64Binary(b64data));
+
+               int orientation;
+               try {
+                       orientation = getExifTransorm(in);
+               } catch (Exception e) {
+                       // no EXIF transform, ok
+                       orientation = -1;
+               }
+
+               in.reset();
+               BufferedImage image = ImageIO.read(in);
+
+               // Note: this code has been found on internet;
+               // thank you anonymous coder.
+               int width = image.getWidth();
+               int height = image.getHeight();
+               AffineTransform affineTransform = new AffineTransform();
+
+               switch (orientation) {
+               case 1:
+                       break;
+               case 2: // Flip X
+                       affineTransform.scale(-1.0, 1.0);
+                       affineTransform.translate(-width, 0);
+                       break;
+               case 3: // PI rotation
+                       affineTransform.translate(width, height);
+                       affineTransform.rotate(Math.PI);
+                       break;
+               case 4: // Flip Y
+                       affineTransform.scale(1.0, -1.0);
+                       affineTransform.translate(0, -height);
+                       break;
+               case 5: // - PI/2 and Flip X
+                       affineTransform.rotate(-Math.PI / 2);
+                       affineTransform.scale(-1.0, 1.0);
+                       break;
+               case 6: // -PI/2 and -width
+                       affineTransform.translate(height, 0);
+                       affineTransform.rotate(Math.PI / 2);
+                       break;
+               case 7: // PI/2 and Flip
+                       affineTransform.scale(-1.0, 1.0);
+                       affineTransform.translate(-height, 0);
+                       affineTransform.translate(0, width);
+                       affineTransform.rotate(3 * Math.PI / 2);
+                       break;
+               case 8: // PI / 2
+                       affineTransform.translate(0, width);
+                       affineTransform.rotate(3 * Math.PI / 2);
+                       break;
+               default:
+                       affineTransform = null;
+                       break;
+               }
+
+               if (affineTransform != null) {
+                       AffineTransformOp affineTransformOp = new AffineTransformOp(
+                                       affineTransform, AffineTransformOp.TYPE_BILINEAR);
+
+                       BufferedImage transformedImage = new BufferedImage(height, width,
+                                       image.getType());
+                       transformedImage = affineTransformOp
+                                       .filter(image, transformedImage);
+
+                       image = transformedImage;
+               }
+               //
+
                return image;
        }
 
@@ -290,4 +360,153 @@ public class StringUtils {
                        return input;
                }
        }
+
+       /**
+        * Return the EXIF transformation flag of this image if any.
+        * 
+        * <p>
+        * Note: this code has been found on internet; thank you anonymous coder.
+        * </p>
+        * 
+        * @param in
+        *            the data {@link InputStream}
+        * 
+        * @return the transformation flag if any
+        * 
+        * @throws IOException
+        *             in case of IO error
+        */
+       static private int getExifTransorm(InputStream in) throws IOException {
+               int[] exif_data = new int[100];
+               int set_flag = 0;
+               int is_motorola = 0;
+
+               /* Read File head, check for JPEG SOI + Exif APP1 */
+               for (int i = 0; i < 4; i++)
+                       exif_data[i] = in.read();
+
+               if (exif_data[0] != 0xFF || exif_data[1] != 0xD8
+                               || exif_data[2] != 0xFF || exif_data[3] != 0xE1)
+                       return -2;
+
+               /* Get the marker parameter length count */
+               int length = (in.read() << 8 | in.read());
+
+               /* Length includes itself, so must be at least 2 */
+               /* Following Exif data length must be at least 6 */
+               if (length < 8)
+                       return -1;
+               length -= 8;
+               /* Read Exif head, check for "Exif" */
+               for (int i = 0; i < 6; i++)
+                       exif_data[i] = in.read();
+
+               if (exif_data[0] != 0x45 || exif_data[1] != 0x78
+                               || exif_data[2] != 0x69 || exif_data[3] != 0x66
+                               || exif_data[4] != 0 || exif_data[5] != 0)
+                       return -1;
+
+               /* Read Exif body */
+               length = length > exif_data.length ? exif_data.length : length;
+               for (int i = 0; i < length; i++)
+                       exif_data[i] = in.read();
+
+               if (length < 12)
+                       return -1; /* Length of an IFD entry */
+
+               /* Discover byte order */
+               if (exif_data[0] == 0x49 && exif_data[1] == 0x49)
+                       is_motorola = 0;
+               else if (exif_data[0] == 0x4D && exif_data[1] == 0x4D)
+                       is_motorola = 1;
+               else
+                       return -1;
+
+               /* Check Tag Mark */
+               if (is_motorola == 1) {
+                       if (exif_data[2] != 0)
+                               return -1;
+                       if (exif_data[3] != 0x2A)
+                               return -1;
+               } else {
+                       if (exif_data[3] != 0)
+                               return -1;
+                       if (exif_data[2] != 0x2A)
+                               return -1;
+               }
+
+               /* Get first IFD offset (offset to IFD0) */
+               int offset;
+               if (is_motorola == 1) {
+                       if (exif_data[4] != 0)
+                               return -1;
+                       if (exif_data[5] != 0)
+                               return -1;
+                       offset = exif_data[6];
+                       offset <<= 8;
+                       offset += exif_data[7];
+               } else {
+                       if (exif_data[7] != 0)
+                               return -1;
+                       if (exif_data[6] != 0)
+                               return -1;
+                       offset = exif_data[5];
+                       offset <<= 8;
+                       offset += exif_data[4];
+               }
+               if (offset > length - 2)
+                       return -1; /* check end of data segment */
+
+               /* Get the number of directory entries contained in this IFD */
+               int number_of_tags;
+               if (is_motorola == 1) {
+                       number_of_tags = exif_data[offset];
+                       number_of_tags <<= 8;
+                       number_of_tags += exif_data[offset + 1];
+               } else {
+                       number_of_tags = exif_data[offset + 1];
+                       number_of_tags <<= 8;
+                       number_of_tags += exif_data[offset];
+               }
+               if (number_of_tags == 0)
+                       return -1;
+               offset += 2;
+
+               /* Search for Orientation Tag in IFD0 */
+               for (;;) {
+                       if (offset > length - 12)
+                               return -1; /* check end of data segment */
+                       /* Get Tag number */
+                       int tagnum;
+                       if (is_motorola == 1) {
+                               tagnum = exif_data[offset];
+                               tagnum <<= 8;
+                               tagnum += exif_data[offset + 1];
+                       } else {
+                               tagnum = exif_data[offset + 1];
+                               tagnum <<= 8;
+                               tagnum += exif_data[offset];
+                       }
+                       if (tagnum == 0x0112)
+                               break; /* found Orientation Tag */
+                       if (--number_of_tags == 0)
+                               return -1;
+                       offset += 12;
+               }
+
+               /* Get the Orientation value */
+               if (is_motorola == 1) {
+                       if (exif_data[offset + 8] != 0)
+                               return -1;
+                       set_flag = exif_data[offset + 9];
+               } else {
+                       if (exif_data[offset + 9] != 0)
+                               return -1;
+                       set_flag = exif_data[offset + 8];
+               }
+               if (set_flag > 8)
+                       return -1;
+
+               return set_flag;
+       }
 }