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https://issues.apache.org/jira/browse/IMAGING-247?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17087016#comment-17087016
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Gary Lucas edited comment on IMAGING-247 at 4/19/20, 1:54 PM:
--------------------------------------------------------------
I took a quick look at your sample image in debugger and it looks like the
first two bytes in the sequence are -127, -1. From the TIFF specification for
PackBits, -127 means "repeat the next byte 128 times". Java uses signed bytes,
so the -1 is the equivalent of 0b1111111, or 255.
So the 255 is not necessarily a faulty value from the perspective of the
PackBits encoding.
But here's the problem... The BitsPerSample tag (see above) defines the data
as having only one bit per sample. But the existing code in ImageDataReader
does not take that into account. It just passes the 255 down to the
PhotometricInterpreterPalette class.
The PhotometricInterpreterPalette runs into a problem because the palette only
defines two states. To make it more robust, it could implement a bounds-check
and return a more informative ImageReadException, but that wouldn't do you much
good.
Not sure how to handle this, but I'll read through the TIFF spec some more and
see what it indicates.
P.S. I did a quick hack to the PhotometricInterpreterPalette just to mask the
low-order bit, and got what looks like an address form. I've attached the
image to this issue.
was (Author: gwlucas):
I took a quick look at your sample image in debugger and it looks like the
first two bytes in the sequence are -127, -1. From the TIFF specification for
PackBits, -127 means "repeat the next byte 128 times". Java uses signed bytes,
so the -1 is the equivalent of 0b1111111, or 255.
So the 255 is not necessarily a faulty value from the perspective of the
PackBits encoding.
But here's the problem... The BitsPerSample tag (see above) defines the data
as having only one bit per sample. But the existing code in ImageDataReader
does not take that into account. It just passes the 255 down to the
PhotometricInterpreterPalette class.
The PhotometricInterpreterPalette runs into a problem because the palette only
defines two states. To make it more robust, it could implement a bounds-check
and return a more informative ImageReadException, but that wouldn't do you much
good.
Not sure how to handle this, but I'll read through the TIFF spec some more and
see what it indicates.
Do you have a JPEG or PNG of what the image ought to look like when decoded?
> crash on reading tiff image
> ---------------------------
>
> Key: IMAGING-247
> URL: https://issues.apache.org/jira/browse/IMAGING-247
> Project: Commons Imaging
> Issue Type: Bug
> Components: Format: TIFF
> Affects Versions: 1.0-alpha1
> Reporter: Robin Morier
> Priority: Major
> Attachments: IMAGING-247.png, neutre.TIFF
>
>
> I get an index out of bounds exception trying to load the attached image.
> {noformat}
> java.lang.ArrayIndexOutOfBoundsException: Index 255 out of bounds for length 2
> at
> org.apache.commons.imaging.formats.tiff.photometricinterpreters.PhotometricInterpreterPalette.interpretPixel(PhotometricInterpreterPalette.java:53)
> at
> org.apache.commons.imaging.formats.tiff.datareaders.DataReaderStrips.interpretStrip(DataReaderStrips.java:179)
> at
> org.apache.commons.imaging.formats.tiff.datareaders.DataReaderStrips.readImageData(DataReaderStrips.java:212)
> at
> org.apache.commons.imaging.formats.tiff.TiffImageParser.getBufferedImage(TiffImageParser.java:659)
> at
> org.apache.commons.imaging.formats.tiff.TiffDirectory.getTiffImage(TiffDirectory.java:163)
> at
> org.apache.commons.imaging.formats.tiff.TiffImageParser.getBufferedImage(TiffImageParser.java:469)
> at
> org.apache.commons.imaging.Imaging.getBufferedImage(Imaging.java:1442)
> at
> org.apache.commons.imaging.Imaging.getBufferedImage(Imaging.java:1404){noformat}
>
> I'm calling getBufferedImage without any parameters.
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