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https://issues.apache.org/jira/browse/IMAGING-126?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13912031#comment-13912031
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Tilman Hausherr commented on IMAGING-126:
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I recently improved the class mentioned in PDFBOX-1734, and one of the things I
did was to set RowsPerStrip to the maximum. The ImageIO implementation did not,
but their solution wasn't so bad, they probably had big strips. (I think I
wrote this issue before that change)
I agree with your author that correctness-of-implementation has the highest
priority. One has to start from there and then try optimizations, and hopefully
have many tests.
Suggestion: put the rowsperstrip as optional parameter. And set a "good"
default.
Re LZW compression: It might be useful to check whether the LZW compressor does
exactly what the algorithm is about. I recently discovered an LZW encoded
segment in a PDF that wasn't optimally encoded. Very weird. (This is not so
difficult to look at that code; the LZW encoder is easier to understand than
the decoder)
> TIFF and PNG images should not be bigger than the ones created by java ImageIO
> ------------------------------------------------------------------------------
>
> Key: IMAGING-126
> URL: https://issues.apache.org/jira/browse/IMAGING-126
> Project: Commons Imaging
> Issue Type: Improvement
> Components: Format: PNG, Format: TIFF
> Affects Versions: 1.0
> Environment: W7
> Reporter: Tilman Hausherr
> Priority: Minor
> Attachments: pdfbox-1870-devicen3-01.png,
> pdfbox-1870-devicen3-01.tif, pdfbox-1870-devicen3.pdf-1.png,
> pdfbox-1870-devicen3.pdf-1.tif
>
>
> I tried to use Apache Imaging for the PDFBOX project (PDFBOX-1734) because of
> problems with setting the tiff resolution in java imageio.
> While the code is pretty nice, I found that the generated images are
> sometimes much bigger in size than the ones generated by java imageio.
> Example:
> pdfbox-1870-devicen3-01.png 50 KB (imageio)
> pdfbox-1870-devicen3.pdf-1.png 70 KB (imaging)
> pdfbox-1870-devicen3-01.tif 401 KB (imageio)
> pdfbox-1870-devicen3.pdf-1.tif 1063 KB (imaging)
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