Package com.itextpdf.kernel.pdf.filters
Class LZWDecoder
java.lang.Object
com.itextpdf.kernel.pdf.filters.LZWDecoder
A class for performing LZW decoding.
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
addStringToTable
(byte[] string) Add a new string to the string table.void
addStringToTable
(byte[] oldString, byte newString) Add a new string to the string table.byte[]
composeString
(byte[] oldString, byte newString) AppendnewString
to the end ofoldString
.void
decode
(byte[] data, OutputStream uncompData) Method to decode LZW compressed data.int
Attempt to get the next code.void
Initialize the string table.void
writeString
(byte[] string) Write out the string just uncompressed.
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Constructor Details
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LZWDecoder
public LZWDecoder()Creates an LZWDecoder instance.
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Method Details
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decode
Method to decode LZW compressed data.- Parameters:
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data
- The compressed data. -
uncompData
- Array to return the uncompressed data in.
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initializeStringTable
public void initializeStringTable()Initialize the string table. -
writeString
public void writeString(byte[] string) Write out the string just uncompressed.- Parameters:
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string
- content to write to the uncompressed data
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addStringToTable
public void addStringToTable(byte[] oldString, byte newString) Add a new string to the string table.- Parameters:
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oldString
- stored string -
newString
- string to be appended to the stored string
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addStringToTable
public void addStringToTable(byte[] string) Add a new string to the string table.- Parameters:
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string
- byte[] to store in the string table
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composeString
public byte[] composeString(byte[] oldString, byte newString) AppendnewString
to the end ofoldString
.- Parameters:
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oldString
- string be appended to -
newString
- string that is to be appended to oldString - Returns:
- combined string
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getNextCode
public int getNextCode()Attempt to get the next code. Exceptions are caught to make this robust to cases wherein the EndOfInformation code has been omitted from a strip. Examples of such cases have been observed in practice.- Returns:
- next code
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