glymur

0.14.7 verified Fri May 01 auth: no python

Python library for reading and writing JPEG 2000 files, wrapping the OpenJPEG library. Current version 0.14.7, requires Python >=3.11, release cadence irregular.

pip install glymur

Common errors

error ImportError: libopenjp2.so.7: cannot open shared object file ↓

cause OpenJPEG library not installed or not in library path.

fix

Install OpenJPEG: apt install libopenjp2-7-dev (Linux) or brew install openjpeg (macOS) or conda install openjpeg.

error AttributeError: 'Jp2k' object has no attribute 'read' ↓

cause Use of deprecated read() method removed in newer versions.

fix

Use direct indexing: data = jp2[:] instead of jp2.read().

error ValueError: The 'crat' attribute is no longer available. ↓

cause Breaking change in version 0.14 removing old attributes.

fix

Use jp2.codestream.compression_ratios instead of jp2.codestream.crat.

Warnings

breaking Version 0.14 dropped support for Python 3.9 and 3.10. Requires Python >=3.11. ↓

fix Upgrade Python to 3.11 or later.

breaking In 0.14, the 'crat' and 'cdef' family of attributes were removed from Codestream. Use 'compression_ratios' and 'color_space' instead. ↓

fix Replace jp2.codestream.crat with jp2.codestream.compression_ratios and jp2.codestream.cdef with jp2.codestream.color_space.

gotcha glymur relies on OpenJPEG system library; missing or incompatible libopenjp2 can cause ImportError or silent failures. ↓

fix Install OpenJPEG via system package manager or conda (e.g., conda install -c conda-forge openjpeg).

gotcha Jp2k object indexing returns a view, not a copy; modifying the slice modifies the underlying data in place. ↓

fix Use .copy() if you need a separate array.

deprecated The glymur.Jp2k.read() method is deprecated in favor of direct indexing (jp2[:]) or waveform reading. ↓

fix Use jp2[:] to read full image data.

Imports

glymur
wrong
```
import Glymur
```
correct
```
import glymur
```
lowercase module name

Jp2k

wrong

from glymur.Jp2k import Jp2k

correct

from glymur import Jp2k

Jp2k is a class in the top-level module

Quickstart

Read and write JPEG 2000 images with glymur.

import glymur

# Open a JPEG 2000 file
jp2 = glymur.Jp2k('input.jp2')
print('Shape:', jp2.shape)
print('Image data:', jp2[:])

# Write a JPEG 2000 file
import numpy as np
data = np.random.randint(0, 256, (256, 256), dtype=np.uint8)
glymur.Jp2k('output.jp2', data=data)  # or use jp2.write(data)