public async Task HandleSelectedImage(ImageItem i)
{
SourceImage = i;
JPEGByteFile file = new JPEGByteFile();
try
{
file = await JPEGAnalyzerService.GetFileSegmentsAsync(i.File);
}
catch (IOException e)
{
Console.WriteLine($"Excepion thrown while reading file segments: {e}");
}
await UpdateDisplayedMetadataSegments(file);
}
public static async Task <JPEGByteFile> GetFileSegmentsAsync(StorageFile file)
{
List <Segment> segments = new List <Segment>();
byte[] fileBytes = new byte[] { };
bool fileReadSucceeded = true;
try
{
IBuffer buffer = await FileIO.ReadBufferAsync(file);
fileBytes = buffer.ToArray();
}
catch (Exception e)
{
Console.WriteLine($"Excepion while reading file bytes: {e}");
fileReadSucceeded = false;
}
if (!fileReadSucceeded)
{
throw new IOException();
}
JPEGByteFile ret = new JPEGByteFile()
{
File = file,
FileBytes = fileBytes
};
if (fileBytes[0] != 0xFF ||
fileBytes[1] != 0xD8)
{
throw new FileFormatException();
}
Int32 cntr = 2;
Int32 effectiveLength = (Int32)fileBytes.Length;
while (cntr < effectiveLength)
{
if (fileBytes[cntr++] != 0xFF)
{
throw new FileFormatException();
}
if (fileBytes[cntr] == 0xD9) // End of image
{
break;
}
Segment segment = new Segment()
{
SegmentStartByteIndexInFile = cntr - 1
};
Int32 segmentDataLength = 0;
try
{
segment.Name = JPEGResources.SegmentNameDictionary[fileBytes[cntr]];
}
catch (Exception e)
{
Console.WriteLine($"Exception thrown during Segment name dictionary lookup: {e}");
throw new FileFormatException();
}
if (JPEGResources.RemovableSegments.Contains(fileBytes[cntr]))
{
segment.Removable = true;
}
if (fileBytes[cntr] == 0xDA) // case there's only SOS segment left (it doesn't include segment length, so it needs special treatment)
{
int compressedImageSegmentLength = 0;
while (!(fileBytes[cntr] == 0xFF && fileBytes[cntr + 1] == 0xD9))
{
cntr++;
compressedImageSegmentLength++;
}
segment.Length = compressedImageSegmentLength - 1;
segment.ExcessBytesAfterSegment = effectiveLength - cntr - 2; // two bytes for the 0xFFD9 EOI marker
segment.SegmentIndexInFile = segments.Count;
segment.SegmentEndByteIndexInFile = cntr + 2;
segments.Add(segment);
break;
}
cntr++;
try
{
byte[] lengthBytes = (byte[])fileBytes.Skip(cntr).Take(2).ToArray();
if (BitConverter.IsLittleEndian)
{
Array.Reverse(lengthBytes);
}
segmentDataLength = (Int32)BitConverter.ToUInt16(lengthBytes, 0);
}
catch (Exception e)
{
Console.WriteLine($"Exception thrown during Segment length exctraction: {e}");
throw new FileFormatException();
}
segment.Length = segmentDataLength;
cntr += 2;
try
{
byte[] rawBytes = fileBytes.Skip(cntr - 4).Take(segmentDataLength + 2).ToArray();
byte[] midBytes = new byte[rawBytes.Length];
int startPivot = 0, endPivot = 0, midBytesPivot = 0, minReadableTextLength = 8;
byte minAscii = 0x20, maxAscii = 0x7f;
while (endPivot < rawBytes.Length)
{
byte currentEndPivotByte = rawBytes[endPivot], currentStartPivotByte = rawBytes[startPivot];
if (currentEndPivotByte >= minAscii && currentEndPivotByte < maxAscii)
{
endPivot++;
continue;
}
if (endPivot - startPivot > minReadableTextLength)
{
while (startPivot < endPivot)
{
midBytes[midBytesPivot++] = rawBytes[startPivot++];
}
}
else
{
startPivot = endPivot;
}
if (midBytesPivot > 0 && midBytes[midBytesPivot - 1] != (byte)'\n')
{
midBytes[midBytesPivot++] = (byte)'\n';
}
startPivot = ++endPivot;
}
byte[] resultBytes = new byte[midBytesPivot];
midBytes.Take(midBytesPivot).ToArray().CopyTo(resultBytes, 0);
segment.Content = resultBytes;
}
catch (Exception e)
{
Console.WriteLine($"Exception thrown during Segment data exctraction: {e}");
throw new FileFormatException();
}
cntr += segmentDataLength - 2; // without the two length bytes which were already added to cntr
segment.SegmentEndByteIndexInFile = cntr;
int excessCntr = 0;
while (cntr + excessCntr + 1 < effectiveLength &&
!(fileBytes[cntr + excessCntr] == 0xFF &&
JPEGResources.SegmentNameDictionary.ContainsKey(fileBytes[cntr + excessCntr + 1])))
{
excessCntr++;
}
cntr += excessCntr;
segment.ExcessBytesAfterSegment = excessCntr;
segment.SegmentIndexInFile = segments.Count;
segments.Add(segment);
}
ret.Segments = segments;
return(ret);
}
public async Task UpdateDisplayedMetadataSegments(JPEGByteFile file)
{
loadingTextBlock.Visibility = Visibility.Visible;
SourceByteFile = file;
ClearBlockChildren();
int segmentCntr = 0;
foreach (Segment s in SourceByteFile.Segments)
{
TextBlock title = new TextBlock
{
Text = s.Name,
Style = (Style)Application.Current.Resources["DetailSubTitleStyle"],
Margin = (Thickness)Application.Current.Resources["SmallTopMargin"]
};
block.Children.Add(title);
TextBlock content = new TextBlock
{
Text = "Length: " + s.Length.ToString() + " B, Excess bytes after segment: " + s.ExcessBytesAfterSegment.ToString() + " B",
Style = (Style)Application.Current.Resources["DetailBodyBaseMediumStyle"]
};
block.Children.Add(content);
StackPanel buttons = new StackPanel
{
Orientation = Orientation.Horizontal,
Spacing = 20
};
if (s.ExcessBytesAfterSegment > 0)
{
Button removeExcessBytesAfterSegmentButton = new Button()
{
Content = "Remove excess bytes",
Tag = "BTN-" + segmentCntr
};
removeExcessBytesAfterSegmentButton.Click += RemoveExcessBytesAfterSegmentButton_Click;
buttons.Children.Add(removeExcessBytesAfterSegmentButton);
}
if (s.Removable)
{
Button removeSegmentButton = new Button()
{
Content = "Remove segment",
Tag = "BTN-" + segmentCntr
};
removeSegmentButton.Click += RemoveSegmentButton_Click;
buttons.Children.Add(removeSegmentButton);
}
if (buttons.Children.Count > 0)
{
block.Children.Add(buttons);
}
if (s.Removable)
{
TextBlock t0 = new TextBlock()
{
Text = "Content:",
Padding = new Thickness(0, 5, 0, 3)
};
block.Children.Add(t0);
TextBlock t = new TextBlock()
{
Text = Encoding.ASCII.GetString(s.Content),
TextWrapping = TextWrapping.Wrap
};
block.Children.Add(t);
}
segmentCntr++;
}
FFTService ImgFFT = new FFTService(file.File);
await ImgFFT.ReadImage();
ImgFFT.ForwardFFT();// Finding 2D FFT of Image
ImgFFT.FFTShift();
await ImgFFT.FFTPlotAsync(ImgFFT.FFTShifted);
TextBlock magnitudeTitle = new TextBlock
{
Text = "Fourier transform magnitude",
Style = (Style)Application.Current.Resources["DetailSubTitleStyle"],
Margin = (Thickness)Application.Current.Resources["SmallTopMargin"]
};
block.Children.Add(magnitudeTitle);
block.Children.Add(new Image()
{
Source = ImgFFT.FourierPlot
});
TextBlock phaseTitle = new TextBlock
{
Text = "Fourier transform phase",
Style = (Style)Application.Current.Resources["DetailSubTitleStyle"],
Margin = (Thickness)Application.Current.Resources["SmallTopMargin"]
};
block.Children.Add(phaseTitle);
block.Children.Add(new Image()
{
Source = ImgFFT.PhasePlot
});
loadingTextBlock.Visibility = Visibility.Collapsed;
}