Ticket #2622 (closed defect: fixed)

Opened 5 years ago

Last modified 5 years ago

Difficult to read large one strip G4 GeoTIFF files

Reported by: warmerdam Owned by: warmerdam
Priority: normal Milestone: 1.5.4
Component: GDAL_Raster Version: 1.5.0
Severity: normal Keywords: gtiff
Cc: gaopeng

Description

Large 1bit one strip G4 compressed tiff files can be very difficult to read in GDAL because the entire file is treated as a singe 8bit block making the memory representation 8 times the size of the decompressed 1bit image.

Libtiff can automatically split uncompressed images into smaller blocks but cannot do this for compressed files. So in theory the problem exists for all one strip compressed images but it is much more common for the 1bit compressed files.

Change History

Changed 5 years ago by warmerdam

  • status changed from new to closed
  • resolution set to fixed
  • milestone set to 1.5.4

I have implemented a new special-case band type - GTiffSplitBitmapBand - which is applied for largish one row, one bit, one band TIFF files in trunk (r15565), and 1.5 branch (r15567). I also added a test case in autotest/gcore/tiff_read.py (r15566).

Changed 5 years ago by warmerdam

  • cc gaopeng added

Changed 5 years ago by warmerdam

Fix a bug when not starting from the beginning in trunk (r15570) and 1.5 branch (r15571).

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