jyapayne/glymur
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

more doc updates

Browse source
This commit is contained in:
jevans 2014-09-25 18:52:19 -04:00
commit 83df953389
4 changed files with 33 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

37
docs/source/how_do_i.rst
View file

@ -7,11 +7,11 @@ How do I...?
================
Jp2k implements slicing via the :py:meth:`__getitem__` method, meaning that
multiple resolution imagery in a JPEG 2000 file can
easily be accessed. For example here's how to retrieve a full resolution and
first lower-resolution image ::
easily be accessed via array-style slicing. For example here's how to
retrieve a full resolution and first lower-resolution image ::
>>> import glymur
>>> jp2file = glymur.data.nemo()
>>> jp2file = glymur.data.nemo() # just a path to a JPEG2000 file
>>> jp2 = glymur.Jp2k(jp2file)
>>> fullres = jp2[:]
>>> print(fullres.shape)
@ -20,8 +20,21 @@ first lower-resolution image ::
>>> print(thumbnail.shape)
(728, 1296, 3)
The :py:meth:`read` method gives many more options for other JPEG 2000 features
such as quality layers.
The :py:meth:`read` method exposes many more options for other JPEG 2000
features such as quality layers.
... write images?
=================
So long as the image data can fit entirely into memory, array-style slicing may
also be used to write JPEG 2000 files.
>>> import glymur, numpy as np
>>> jp2 = glymur.Jp2k('zeros.jp2', mode='wb')
>>> jp2[:] = np.zeros((640, 480), dtype=np.uint8)
The :py:meth:`write` method exposes many more options for other JPEG 2000
features. You should have OpenJPEG version 1.5 or more recent before writing
JPEG 2000 images.
... display metadata?
=====================
@ -328,10 +341,10 @@ is currently limited to XML and UUID boxes.
... create an image with an alpha layer?
========================================
OpenJPEG can create JP2 files with more than 3 components (requires
the development version of OpenJPEG), but by default, any extra components are
not described as such. In order to do so, we need to rewrap such
an image in a set of boxes that includes a channel definition box.
OpenJPEG can create JP2 files with more than 3 components (use version 2.1.0+
for this), but by default, any extra components are not described
as such. In order to do so, we need to rewrap such an image in a
set of boxes that includes a channel definition box.
This example is based on SciPy example code found at
http://scipy-lectures.github.io/advanced/image_processing/#basic-manipulations .
@ -389,7 +402,11 @@ Here's how the Preview application on the mac shows the RGBA image.
... work with XMP UUIDs?
========================
XMP is metadata on steroids.
`Wikipedia <http://en.wikipedia.org/wiki/Extensible_Metadata_Platform>`_ states
that "The Extensible Metadata Platform (XMP) is an ISO standard,
originally created by Adobe Systems Inc., for the creation, processing
and interchange of standardized and custom metadata for all kinds
of resources."
The example JP2 file shipped with glymur has an XMP UUID. ::