- options
- Provides input parameters for the decompression process.
Visual Basic (Declaration) | |
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Public Function StartDecompress( _ ByVal options As CodecsStartDecompressOptions _ ) As Object |
Visual Basic (Usage) | ![]() |
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Dim instance As RasterCodecs Dim options As CodecsStartDecompressOptions Dim value As Object value = instance.StartDecompress(options) |
C# | |
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public object StartDecompress( CodecsStartDecompressOptions options ) |
C++/CLI | |
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public: Object^ StartDecompress( CodecsStartDecompressOptions options ) |
Parameters
- options
- Provides input parameters for the decompression process.
Return Value
An object that identifies the decompression process. This same object must be passed to the Decompress(Object,Byte[],Int32,Int32,Int32,Int32,Int32,Int32,CodecsDecompressDataFlags) and StopDecompress methods.
Visual Basic | ![]() |
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' This sample loads raw data from a PackBits TIF file ' PackBits.tif is a 24-bit tif packbits compressed file ' PackBits.tif has 46 strips of packbits data ' The strip information is obtained by reading the TIF tags TAG_STRIPOFFSETS and TAG_STRIPBYTECOUNTS ' The strips are directly read and fed to the Compress method Private Sub LoadRawPackbitsStrips(ByVal packTifFile As String) Dim codecs As RasterCodecs = New RasterCodecs() Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Decompress.bmp") Dim imageInfo As CodecsImageInfo = codecs.GetInformation(packTifFile, False) ' StartDecompress Dim options As CodecsStartDecompressOptions = CodecsStartDecompressOptions.Empty options.DataType = CodecsStartDecompressDataType.Strips options.Format = RasterImageFormat.RawPackBits options.Width = imageInfo.Width options.Height = imageInfo.Height options.BitsPerPixel = imageInfo.BitsPerPixel options.ViewPerspective = imageInfo.ViewPerspective options.RawOrder = imageInfo.Order options.LoadOrder = CodecsLoadByteOrder.BgrOrGray options.XResolution = imageInfo.XResolution options.YResolution = imageInfo.YResolution options.TiffPhotometricInterpretation = CodecsTiffPhotometricInterpretation.Rgb Dim decompressObject As Object = codecs.StartDecompress(options) ' Decompress Const TAG_STRIPOFFSETS As Integer = &H111 Const TAG_STRIPBYTECOUNTS As Integer = &H117 Const TAG_ROWSPERSTRIP As Integer = &H116 Const MAX_STRIPS As Integer = 1000 Dim stripOffsets As Integer() = New Integer(MAX_STRIPS - 1) {} Dim stripSizes As Integer() = New Integer(MAX_STRIPS - 1) {} Dim rowsPerStripBuffer As Integer() = New Integer(0) {} Dim maxIndex As Integer = ReadTag(codecs, packTifFile, TAG_STRIPOFFSETS, stripOffsets) ReadTag(codecs, packTifFile, TAG_STRIPBYTECOUNTS, stripSizes) ReadTag(codecs, packTifFile, TAG_ROWSPERSTRIP, rowsPerStripBuffer) Dim rowsPerStrip As Integer = rowsPerStripBuffer(0) Dim fs As FileStream = File.OpenRead(packTifFile) Const row As Integer = 0 ' Note: this parameter is ignored for strips Const column As Integer = 0 ' Column offset of tile Dim index As Integer = 0 Do While index < maxIndex ' seek to the first strip fs.Seek(stripOffsets(index), SeekOrigin.Begin) Dim buffer As Byte() = New Byte(stripSizes(index) - 1) {} fs.Read(buffer, 0, buffer.Length) ' Calculate the height of uncompressed strip/tile Dim height As Integer = rowsPerStrip If index = (maxIndex - 1) Then ' fewer rows per strip height = imageInfo.Height - (maxIndex - 1) * rowsPerStrip End If codecs.Decompress(decompressObject, buffer, 0, buffer.Length, imageInfo.Width, height, row, column, CodecsDecompressDataFlags.Complete) index += 1 Loop fs.Close() ' StopDecompress Dim image As RasterImage = codecs.StopDecompress(decompressObject) ' 'image' contains the uncompressed image codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24) image.Dispose() ' Clean up codecs.Dispose() End Sub ' Returns maximum index Private Function ReadTag(ByVal codecs As RasterCodecs, ByVal fileName As String, ByVal tagId As Integer, ByVal stripArray As Integer()) As Integer Dim tag As RasterTagMetadata = codecs.ReadTag(fileName, 1, tagId) Dim data As Integer() = tag.ToInt32() data.CopyTo(stripArray, 0) Return tag.Count End Function Public NotInheritable Class LEAD_VARS Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images" End Class |
C# | ![]() |
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// This sample loads raw data from a PackBits TIF file // PackBits.tif is a 24-bit tif packbits compressed file // PackBits.tif has 46 strips of packbits data // The strip information is obtained by reading the TIF tags TAG_STRIPOFFSETS and TAG_STRIPBYTECOUNTS // The strips are directly read and fed to the Compress method void LoadRawPackbitsStrips(string packTifFile) { RasterCodecs codecs = new RasterCodecs(); string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Decompress.bmp"); CodecsImageInfo imageInfo = codecs.GetInformation(packTifFile, false); // StartDecompress CodecsStartDecompressOptions options = CodecsStartDecompressOptions.Empty; options.DataType = CodecsStartDecompressDataType.Strips; options.Format = RasterImageFormat.RawPackBits; options.Width = imageInfo.Width; options.Height = imageInfo.Height; options.BitsPerPixel = imageInfo.BitsPerPixel; options.ViewPerspective = imageInfo.ViewPerspective; options.RawOrder = imageInfo.Order; options.LoadOrder = CodecsLoadByteOrder.BgrOrGray; options.XResolution = imageInfo.XResolution; options.YResolution = imageInfo.YResolution; options.TiffPhotometricInterpretation = CodecsTiffPhotometricInterpretation.Rgb; object decompressObject = codecs.StartDecompress(options); // Decompress const int TAG_STRIPOFFSETS = 0x111; const int TAG_STRIPBYTECOUNTS = 0x117; const int TAG_ROWSPERSTRIP = 0x116; const int MAX_STRIPS = 1000; int[] stripOffsets = new int[MAX_STRIPS]; int[] stripSizes = new int[MAX_STRIPS]; int[] rowsPerStripBuffer = new int[1]; int maxIndex = ReadTag(codecs, packTifFile, TAG_STRIPOFFSETS, stripOffsets); ReadTag(codecs, packTifFile, TAG_STRIPBYTECOUNTS, stripSizes); ReadTag(codecs, packTifFile, TAG_ROWSPERSTRIP, rowsPerStripBuffer); int rowsPerStrip = rowsPerStripBuffer[0]; FileStream fs = File.OpenRead(packTifFile); const int row = 0; // Note: this parameter is ignored for strips const int column = 0; // Column offset of tile for(int index = 0; index < maxIndex; index++) { // seek to the first strip fs.Seek(stripOffsets[index], SeekOrigin.Begin); byte[] buffer = new byte[stripSizes[index]]; fs.Read(buffer, 0, buffer.Length); // Calculate the height of uncompressed strip/tile int height = rowsPerStrip; if(index == (maxIndex - 1)) { // fewer rows per strip height = imageInfo.Height - (maxIndex - 1) * rowsPerStrip; } codecs.Decompress( decompressObject, buffer, 0, buffer.Length, imageInfo.Width, height, row, column, CodecsDecompressDataFlags.Complete); } fs.Close(); // StopDecompress RasterImage image = codecs.StopDecompress(decompressObject); // 'image' contains the uncompressed image codecs.Save(image, destFileName, RasterImageFormat.Bmp, 24); image.Dispose(); // Clean up codecs.Dispose(); } // Returns maximum index int ReadTag(RasterCodecs codecs, string fileName, int tagId, int[] stripArray) { RasterTagMetadata tag = codecs.ReadTag(fileName, 1, tagId); int[] data = tag.ToInt32(); data.CopyTo(stripArray, 0); return tag.Count; } static class LEAD_VARS { public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images"; } |
SilverlightCSharp | ![]() |
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SilverlightVB | ![]() |
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Initializes the buffered decompression engine. The decompression is then carried out using the Decompress(Object,Byte[],Int32,Int32,Int32,Int32,Int32,Int32,CodecsDecompressDataFlags) method. It is ended by the StopDecompress method.
Currently, raw JPEG must contain all the Huffman tables encoded. That is, it must be a readable JPEG file.
Target Platforms: Silverlight, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only)