Class Average
java.lang.Object
org.apache.pdfbox.pdmodel.graphics.predictor.PredictorAlgorithm
org.apache.pdfbox.pdmodel.graphics.predictor.Average
We can use raw on the right hand side of
the decoding formula because it is already decoded.
average(i,j) = raw(i,j) + (raw(i-1,j)+raw(i,j-1)/2
decoding
raw(i,j) = avarage(i,j) - (raw(i-1,j)+raw(i,j-1)/2
- Version:
- $Revision: 1.3 $
- Author:
- xylifyx@yahoo.co.uk
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
decodeLine
(byte[] src, byte[] dest, int srcDy, int srcOffset, int destDy, int destOffset) decode line of pixel data in src from src_offset and width*bpp bytes forward, put the decoded bytes into dest.void
encodeLine
(byte[] src, byte[] dest, int srcDy, int srcOffset, int destDy, int destOffset) Not an optimal version, but close to the def.Methods inherited from class org.apache.pdfbox.pdmodel.graphics.predictor.PredictorAlgorithm
aboveLeftPixel, abovePixel, checkBufsiz, decode, encode, getBpp, getFilter, getHeight, getWidth, leftPixel, main, setBpp, setHeight, setWidth
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Constructor Details
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Average
public Average()
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Method Details
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encodeLine
public void encodeLine(byte[] src, byte[] dest, int srcDy, int srcOffset, int destDy, int destOffset) Not an optimal version, but close to the def. encode line of pixel data in src from srcOffset and width*bpp bytes forward, put the decoded bytes into dest.- Specified by:
encodeLine
in classPredictorAlgorithm
- Parameters:
src
- raw image datadest
- encoded datasrcDy
- byte offset between linessrcOffset
- beginning of line datadestDy
- byte offset between linesdestOffset
- beginning of line data
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decodeLine
public void decodeLine(byte[] src, byte[] dest, int srcDy, int srcOffset, int destDy, int destOffset) decode line of pixel data in src from src_offset and width*bpp bytes forward, put the decoded bytes into dest.- Specified by:
decodeLine
in classPredictorAlgorithm
- Parameters:
src
- encoded image datadest
- raw datasrcDy
- byte offset between linessrcOffset
- beginning of line datadestDy
- byte offset between linesdestOffset
- beginning of line data
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