Opened 12 years ago

Closed 11 years ago

#3923 closed enhancement (wontfix)

[PATCH] MrSID with JPEG2K compressed NITFs don't use block size from JPEG2K data

Reported by: klaricmn Owned by: warmerdam
Priority: normal Milestone: 1.8.1
Component: default Version: unspecified
Severity: normal Keywords: MrSID JPEG2K NITF
Cc: bclaywell, kirk

Description

The attached patch improves the block size specification in the GDAL MrSID driver. This modification causes the the tile size returned by the J2KImageReader to be used as the block size for the image in the case of JPEG2K data embedded in NITFs. Although JPEG2K compression supports efficient reads of arbitrary size, we've found it useful to have the tile sizes used in the underlying JPEG2K structure to be used as the block size for NITFs as opposed to the arbitrary 1024x128 that usually resulted before this patch.

Attachments (1)

mrsid_proper_block_size.patch (2.0 KB ) - added by klaricmn 12 years ago.

Download all attachments as: .zip

Change History (5)

by klaricmn, 12 years ago

comment:1 by bclaywell, 12 years ago

Cc: bclaywell added

comment:2 by Even Rouault, 12 years ago

Cc: kirk added

comment:3 by Even Rouault, 11 years ago

Summary: MrSID with JPEG2K compressed NITFs don't use block size from JPEG2K data[PATCH] MrSID with JPEG2K compressed NITFs don't use block size from JPEG2K data

comment:4 by warmerdam, 11 years ago

Resolution: wontfix
Status: newclosed

Note that many jpeg2000 data streams use only one jpeg2000 tile even for large files. So I don't think it would be appropriate to incorporate this patch in the default implementation. I believe it is only appropriate for particular (nonblocking) access patterns or cases where you know the jpeg2000 data streams will not have very large tiles.

The patch will remain available here in trac.

It might be appropriate to reference it from the MrSID developer page at:

http://trac.osgeo.org/gdal/wiki/MrSID

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