public virtual void TestGetInt32()
{
Sharpen.Tests.AreEqual(-1, CreateReader(new sbyte[] { unchecked ((sbyte)0xff), unchecked ((sbyte)0xff), unchecked ((sbyte)0xff), unchecked ((sbyte)0xff) }).GetInt32());
sbyte[] buffer = new sbyte[] { unchecked ((int)(0x00)), unchecked ((int)(0x01)), unchecked ((int)(0x02)), unchecked ((int)(0x03)), unchecked ((int)(0x04)), unchecked ((int)(0x05)), unchecked ((int)(0x06)), unchecked ((int)(0x07)) };
SequentialReader reader = CreateReader(buffer);
Sharpen.Tests.AreEqual(unchecked ((int)(0x00010203)), reader.GetInt32());
Sharpen.Tests.AreEqual(unchecked ((int)(0x04050607)), reader.GetInt32());
reader = CreateReader(buffer);
reader.SetMotorolaByteOrder(false);
Sharpen.Tests.AreEqual(unchecked ((int)(0x03020100)), reader.GetInt32());
Sharpen.Tests.AreEqual(unchecked ((int)(0x07060504)), reader.GetInt32());
}
public virtual void TestGetInt32_OutOfBounds()
{
try
{
SequentialReader reader = CreateReader(new sbyte[3]);
reader.GetInt32();
NUnit.Framework.Assert.Fail("Exception expected");
}
catch (IOException ex)
{
Sharpen.Tests.AreEqual("End of data reached.", ex.Message);
}
}
/// <exception cref="Com.Drew.Imaging.Png.PngProcessingException"/>
/// <exception cref="System.IO.IOException"/>
public virtual Iterable<PngChunk> Extract(SequentialReader reader, ICollection<PngChunkType> desiredChunkTypes)
{
//
// PNG DATA STREAM
//
// Starts with a PNG SIGNATURE, followed by a sequence of CHUNKS.
//
// PNG SIGNATURE
//
// Always composed of these bytes: 89 50 4E 47 0D 0A 1A 0A
//
// CHUNK
//
// 4 - length of the data field (unsigned, but always within 31 bytes), may be zero
// 4 - chunk type, restricted to [65,90] and [97,122] (A-Za-z)
// * - data field
// 4 - CRC calculated from chunk type and chunk data, but not length
//
// CHUNK TYPES
//
// Critical Chunk Types:
//
// IHDR - image header, always the first chunk in the data stream
// PLTE - palette table, associated with indexed PNG images
// IDAT - image data chunk, of which there may be many
// IEND - image trailer, always the last chunk in the data stream
//
// Ancillary Chunk Types:
//
// Transparency information: tRNS
// Colour space information: cHRM, gAMA, iCCP, sBIT, sRGB
// Textual information: iTXt, tEXt, zTXt
// Miscellaneous information: bKGD, hIST, pHYs, sPLT
// Time information: tIME
//
reader.SetMotorolaByteOrder(true);
// network byte order
if (!Arrays.Equals(PngSignatureBytes, reader.GetBytes(PngSignatureBytes.Length)))
{
throw new PngProcessingException("PNG signature mismatch");
}
bool seenImageHeader = false;
bool seenImageTrailer = false;
IList<PngChunk> chunks = new AList<PngChunk>();
ICollection<PngChunkType> seenChunkTypes = new HashSet<PngChunkType>();
while (!seenImageTrailer)
{
// Process the next chunk.
int chunkDataLength = reader.GetInt32();
PngChunkType chunkType = new PngChunkType(reader.GetBytes(4));
sbyte[] chunkData = reader.GetBytes(chunkDataLength);
// Skip the CRC bytes at the end of the chunk
// TODO consider verifying the CRC value to determine if we're processing bad data
reader.Skip(4);
if (seenChunkTypes.Contains(chunkType) && !chunkType.AreMultipleAllowed())
{
throw new PngProcessingException(Sharpen.Extensions.StringFormat("Observed multiple instances of PNG chunk '%s', for which multiples are not allowed", chunkType));
}
if (chunkType.Equals(PngChunkType.Ihdr))
{
seenImageHeader = true;
}
else
{
if (!seenImageHeader)
{
throw new PngProcessingException(Sharpen.Extensions.StringFormat("First chunk should be '%s', but '%s' was observed", PngChunkType.Ihdr, chunkType));
}
}
if (chunkType.Equals(PngChunkType.Iend))
{
seenImageTrailer = true;
}
if (desiredChunkTypes == null || desiredChunkTypes.Contains(chunkType))
{
chunks.Add(new PngChunk(chunkType, chunkData));
}
seenChunkTypes.Add(chunkType);
}
return chunks.AsIterable();
}
public virtual void Extract(SequentialReader reader, Com.Drew.Metadata.Metadata metadata)
{
BmpHeaderDirectory directory = metadata.GetOrCreateDirectory<BmpHeaderDirectory>();
// FILE HEADER
//
// 2 - magic number (0x42 0x4D = "BM")
// 4 - size of BMP file in bytes
// 2 - reserved
// 2 - reserved
// 4 - the offset of the pixel array
//
// BITMAP INFORMATION HEADER
//
// The first four bytes of the header give the size, which is a discriminator of the actual header format.
// See this for more information http://en.wikipedia.org/wiki/BMP_file_format
//
// BITMAPINFOHEADER (size = 40)
//
// 4 - size of header
// 4 - pixel width (signed)
// 4 - pixel height (signed)
// 2 - number of colour planes (must be set to 1)
// 2 - number of bits per pixel
// 4 - compression being used (needs decoding)
// 4 - pixel data length (not total file size, just pixel array)
// 4 - horizontal resolution, pixels/meter (signed)
// 4 - vertical resolution, pixels/meter (signed)
// 4 - number of colours in the palette (0 means no palette)
// 4 - number of important colours (generally ignored)
//
// BITMAPCOREHEADER (size = 12)
//
// 4 - size of header
// 2 - pixel width
// 2 - pixel height
// 2 - number of colour planes (must be set to 1)
// 2 - number of bits per pixel
//
// COMPRESSION VALUES
//
// 0 = None
// 1 = RLE 8-bit/pixel
// 2 = RLE 4-bit/pixel
// 3 = Bit field (or Huffman 1D if BITMAPCOREHEADER2 (size 64))
// 4 = JPEG (or RLE-24 if BITMAPCOREHEADER2 (size 64))
// 5 = PNG
// 6 = Bit field
reader.SetMotorolaByteOrder(false);
try
{
int magicNumber = reader.GetUInt16();
if (magicNumber != unchecked((int)(0x4D42)))
{
directory.AddError("Invalid BMP magic number");
return;
}
// skip past the rest of the file header
reader.Skip(4 + 2 + 2 + 4);
int headerSize = reader.GetInt32();
directory.SetInt(BmpHeaderDirectory.TagHeaderSize, headerSize);
// We expect the header size to be either 40 (BITMAPINFOHEADER) or 12 (BITMAPCOREHEADER)
if (headerSize == 40)
{
// BITMAPINFOHEADER
directory.SetInt(BmpHeaderDirectory.TagImageWidth, reader.GetInt32());
directory.SetInt(BmpHeaderDirectory.TagImageHeight, reader.GetInt32());
directory.SetInt(BmpHeaderDirectory.TagColourPlanes, reader.GetInt16());
directory.SetInt(BmpHeaderDirectory.TagBitsPerPixel, reader.GetInt16());
directory.SetInt(BmpHeaderDirectory.TagCompression, reader.GetInt32());
// skip the pixel data length
reader.Skip(4);
directory.SetInt(BmpHeaderDirectory.TagXPixelsPerMeter, reader.GetInt32());
directory.SetInt(BmpHeaderDirectory.TagYPixelsPerMeter, reader.GetInt32());
directory.SetInt(BmpHeaderDirectory.TagPaletteColourCount, reader.GetInt32());
directory.SetInt(BmpHeaderDirectory.TagImportantColourCount, reader.GetInt32());
}
else
{
if (headerSize == 12)
{
directory.SetInt(BmpHeaderDirectory.TagImageWidth, reader.GetInt16());
directory.SetInt(BmpHeaderDirectory.TagImageHeight, reader.GetInt16());
directory.SetInt(BmpHeaderDirectory.TagColourPlanes, reader.GetInt16());
directory.SetInt(BmpHeaderDirectory.TagBitsPerPixel, reader.GetInt16());
}
else
{
directory.AddError("Unexpected DIB header size: " + headerSize);
}
}
}
catch (IOException)
{
directory.AddError("Unable to read BMP header");
}
}