Package net.sourceforge.jiu.codecs.jpeg
Class JPEGMarkerReader
java.lang.Object
net.sourceforge.jiu.codecs.jpeg.JPEGMarkerReader
Static helper methods to read various JPEG bitstream headers from a
DataInput source into objects of the appropriate
data classes.
Objects are then added to a JPEGData object.- Since:
- 0.14.0
- Author:
- Marco Schmidt
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Constructor Summary
ConstructorsModifierConstructorDescriptionprivatePrivate constructor to prevent instantiation. -
Method Summary
Modifier and TypeMethodDescriptionstatic voidreadHuffmanTables(DataInput in, JPEGData jpegData, int length) static voidreadQuantizationTables(DataInput in, JPEGData jpegData, int length) Read quantization tables from a DQT marker.static voidreadStartOfFrame(DataInput in, JPEGData jpegData, int marker, int length) static voidreadStartOfScan(DataInput in, JPEGData jpegData, int length) Read an SOS (start of scan) marker.
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Constructor Details
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JPEGMarkerReader
private JPEGMarkerReader()Private constructor to prevent instantiation.
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Method Details
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readHuffmanTables
public static void readHuffmanTables(DataInput in, JPEGData jpegData, int length) throws InvalidFileStructureException, IOException -
readQuantizationTables
public static void readQuantizationTables(DataInput in, JPEGData jpegData, int length) throws InvalidFileStructureException, IOException Read quantization tables from a DQT marker. P&M 7.8.3, p. 118f.- Parameters:
jpegData- data object which will store the table(s)length- length of marker- Throws:
InvalidFileStructureException- if the DQT contains invalid dataIOException- on reading errors
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readStartOfFrame
public static void readStartOfFrame(DataInput in, JPEGData jpegData, int marker, int length) throws InvalidFileStructureException, IOException, UnsupportedTypeException -
readStartOfScan
public static void readStartOfScan(DataInput in, JPEGData jpegData, int length) throws InvalidFileStructureException, IOException, UnsupportedTypeException Read an SOS (start of scan) marker. P&M 7.6, p. 113.- Parameters:
in- source to read marker information fromjpegData-JPEGDataobject to update with information from the markerlength- size of marker in bytes- Throws:
InvalidFileStructureException- if encountered data does not follow the JPEG standardIOException- on I/O errorsUnsupportedTypeException- if encountered data is valid but unsupported by this package
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