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Capture parses EXIF data and rotates image based on EXIF_Orientation
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,194 @@ | ||
| using System; | ||
| using System.Net; | ||
| using System.Windows; | ||
| using System.Windows.Controls; | ||
| using System.Windows.Documents; | ||
| using System.Windows.Ink; | ||
| using System.Windows.Input; | ||
| using System.Windows.Media; | ||
| using System.Windows.Media.Animation; | ||
| using System.Windows.Shapes; | ||
| using System.IO; | ||
| using System.Windows.Media.Imaging; | ||
| using System.Diagnostics; | ||
|
|
||
| namespace WP7CordovaClassLib.Cordova.Commands | ||
| { | ||
| public class ImageExifOrientation | ||
| { | ||
| public const int Portrait = 1; | ||
| public const int PortraitUpsideDown = 3; | ||
| public const int LandscapeLeft = 6; | ||
| public const int LandscapeRight = 8; | ||
| } | ||
|
|
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| public class ImageExifHelper | ||
| { | ||
|
|
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| public static Stream RotateStream(Stream stream, int angle) | ||
| { | ||
| stream.Position = 0; | ||
| if (angle % 90 != 0 || angle < 0) | ||
| { | ||
| throw new ArgumentException(); | ||
| } | ||
| if (angle % 360 == 0) | ||
| { | ||
| return stream; | ||
| } | ||
|
|
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| angle = angle % 360; | ||
|
|
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| BitmapImage bitmap = new BitmapImage(); | ||
| bitmap.SetSource(stream); | ||
| WriteableBitmap wbSource = new WriteableBitmap(bitmap); | ||
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| WriteableBitmap wbTarget = null; | ||
|
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| int srcPixelWidth = wbSource.PixelWidth; | ||
| int srcPixelHeight = wbSource.PixelHeight; | ||
|
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| if (angle % 180 == 0) | ||
| { | ||
| wbTarget = new WriteableBitmap(srcPixelWidth, srcPixelHeight); | ||
| } | ||
| else | ||
| { | ||
| wbTarget = new WriteableBitmap(srcPixelHeight, srcPixelWidth); | ||
| } | ||
|
|
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| int destPixelWidth = wbTarget.PixelWidth; | ||
| int[] srcPxls = wbSource.Pixels; | ||
| int[] destPxls = wbTarget.Pixels; | ||
|
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| // this ugly if/else is to avoid a conditional check for every pixel | ||
| if (angle == 90) { | ||
| for (int x = 0; x < srcPixelWidth; x++) { | ||
| for (int y = 0; y < srcPixelHeight; y++) { | ||
| destPxls[(srcPixelHeight - y - 1) + (x * destPixelWidth)] = srcPxls[x + y * srcPixelWidth]; | ||
| } | ||
| } | ||
| } | ||
| else if (angle == 180) { | ||
| for (int x = 0; x < srcPixelWidth; x++) { | ||
| for (int y = 0; y < srcPixelHeight; y++) { | ||
| destPxls[(srcPixelWidth - x - 1) + (srcPixelHeight - y - 1) * srcPixelWidth] = srcPxls[x + y * srcPixelWidth]; | ||
| } | ||
| } | ||
| } | ||
| else if (angle == 270) { | ||
| for (int x = 0; x < srcPixelWidth; x++) { | ||
| for (int y = 0; y < srcPixelHeight; y++) { | ||
| destPxls[y + (srcPixelWidth - x - 1) * destPixelWidth] = srcPxls[x + y * srcPixelWidth]; | ||
| } | ||
| } | ||
| } | ||
|
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| MemoryStream targetStream = new MemoryStream(); | ||
| wbTarget.SaveJpeg(targetStream, destPixelWidth, wbTarget.PixelHeight, 0, 100); | ||
| return targetStream; | ||
| } | ||
|
|
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| public static int getImageOrientationFromStream(Stream imgStream) | ||
| { | ||
|
|
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| // 0xFFD8 : jpgHeader | ||
| // 0xFFE1 : | ||
| // 0x???? : length of exif data | ||
| // 0x????, 0x???? : Chars 'E','x','i','f' | ||
| // 0x0000 : 2 empty bytes | ||
| // <== mark beginning of tags SIZE:ID:VALUE | ||
| // 0x???? : 'II' or 'MM' for Intel or Motorola ( always getting II on my WP7 devices ), determins littleEndian-ness | ||
| // 0x002A : marker value | ||
| // 0x???? : offset to the Image File Data | ||
|
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| // XXXX possible space before actual tag data ... we skip to mark + offset | ||
|
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| // 0x???? number of exif tags present | ||
|
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| // make sure we are at the begining | ||
| imgStream.Seek(0, SeekOrigin.Begin); | ||
| BinaryReader reader = new BinaryReader(imgStream); | ||
|
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| byte[] jpgHdr = reader.ReadBytes(2); // always (0xFFD8) | ||
|
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| byte start = reader.ReadByte(); // 0xFF | ||
| byte index = reader.ReadByte(); // 0xE1 | ||
|
|
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| while (start == 0xFF && index != 0xE1) // This never seems to happen, todo: optimize | ||
| { | ||
| // Get the data length | ||
| ushort dLen = BitConverter.ToUInt16(reader.ReadBytes(2), 0); | ||
| // skip along | ||
| reader.BaseStream.Seek(dLen - 2, SeekOrigin.Current); | ||
| start = reader.ReadByte(); | ||
| index = reader.ReadByte(); | ||
| } | ||
|
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| // It's only success if we found the 0xFFE1 marker | ||
| if (start != 0xFF || index != 0xE1) | ||
| { | ||
| // throw new Exception("Could not find Exif data block"); | ||
| Debug.WriteLine("Did not find EXIF data"); | ||
| return 0; | ||
| } | ||
|
|
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| // read 2 byte length of EXIF data | ||
| ushort exifLen = BitConverter.ToUInt16(reader.ReadBytes(2), 0); | ||
| String exif = ""; // build the string | ||
| for (var n = 0; n < 4; n++) | ||
| { | ||
| exif += reader.ReadChar(); | ||
| } | ||
| if (exif != "Exif") | ||
| { | ||
| // did not find exif data ... | ||
| Debug.WriteLine("Did not find EXIF data"); | ||
| return 0; | ||
| } | ||
|
|
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| // read 2 empty bytes | ||
| //ushort emptyBytes = BitConverter.ToUInt16(reader.ReadBytes(2), 0); | ||
| reader.ReadBytes(2); | ||
|
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| long headerMark = reader.BaseStream.Position; // where are we now <== | ||
|
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| //bool isLEndian = (reader.ReadChar() + "" + reader.ReadChar()) == "II"; | ||
| reader.ReadBytes(2); // 'II' or 'MM', but we don't care | ||
|
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| if (0x002A != BitConverter.ToUInt16(reader.ReadBytes(2), 0)) | ||
| { | ||
| Debug.WriteLine("Error in data != 0x002A"); | ||
| return 0; | ||
| } | ||
|
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| // Get the offset to the IFD (image file directory) | ||
| ushort imgOffset = BitConverter.ToUInt16(reader.ReadBytes(2), 0); | ||
|
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| imgStream.Position = headerMark + imgOffset; | ||
| ushort tagCount = BitConverter.ToUInt16(reader.ReadBytes(2), 0); | ||
| for (ushort x = 0; x < tagCount; x++) | ||
| { | ||
| // Orientation = 0x112, aka 274 | ||
| if (0x112 == BitConverter.ToUInt16(reader.ReadBytes(2), 0)) | ||
| { | ||
| ushort dType = BitConverter.ToUInt16(reader.ReadBytes(2), 0); | ||
| // don't care .. | ||
| uint comps = reader.ReadUInt32(); | ||
| byte[] tagData = reader.ReadBytes(4); | ||
| int orientation = (int)tagData[0]; | ||
| Debug.WriteLine("orientation = " + orientation.ToString()); | ||
| return orientation; | ||
| // 6 means rotate clockwise 90 deg | ||
| // 8 means rotate counter-clockwise 90 deg | ||
| // 1 means all is good | ||
| // 3 means flip vertical | ||
| } | ||
| // skip to the next item, 12 bytes each | ||
| reader.BaseStream.Seek(10, SeekOrigin.Current); | ||
| } | ||
| return 0; | ||
| } | ||
|
|
||
| } | ||
| } |
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