Spectral

New Features
------------

* Rendering functions accept an "ignore" keyword to indicate a bad data value
that will be ignored when calculating color histogram stretches.

* Added `iterator_ij` to iterate over all pixel coordinates for a given
image mask.

* Added `expand_binary_mask_for_window` to expand an image mask to include
all pixels within a fixed size window around each masked pixel.

* Added support for bad band lists (bbl) in ENVI headers and suppress display
of bad bands in spectral plots

* Added optional support for non-lowercase ENVI header parameter names (issue 63).

Changes
-------

* `principal_components` also accepts a `GaussianStats` object, which can
avoid the need to recompute image/class statistics.

* Added a `SpyException` base class for package-specific exceptions.

* Added "raw" to the list of checked ENVI image data file extensions.

Bug Fixes
---------

* Fixed a bug that potentially produced incorrect results in `map_class_ids`
(issue 53).

* Removed unecessary import that cause python3 compatibility error in
`aviris.open` (issue 54).

* Removed `has_key` call breaking python3 compatibility (issue 56).

Changes
- Improved handling of ENVI header files:
- If "header offset" is missing, assume the offset is 0.
- Stricter check for "ENVI" in the first line of the file.
- [Issue 42] More-informative exceptions are raised when a problem is
encountered while reading and ENVI header.
- [Issue 46] No longer defaulting `band_quantity` to "Wavelength".

Bug Fixes
- [Issue 38 and 39] The `tostring` method has been deprecated in newer
versions of PIL/Pillow. Using `tobytes` now and falling back to `tostring`
if it fails.
- [Issue 40] An exception was raised when trying to get a pixel's row/col
by CTRL-SHIFT-clicking in the ND window display.
- [Issue 44] Matplotlib was being set to interactive mode even if no SPy
windows were displayed. This would affect behavior of other code using
Matplotlib. Interactive mode is now set only once the first display is
requested.
- [Issue 49] `GaussianClassifier` and `MahalanobisDistanceClassifier` method
`classify_image` was failing when applied to an object that was not a
numpy.ndarray (e.g., a `SpyFile` or `TransformedImage`).

New Features
- Functions `map_class_ids` and `map_classes` were added for mapping class
indices between images.
- `view_nd` now accepts custom axis labels.
- `ImageArray` and `SpyFile` have `asarray` method that provides numpy
array interface.

Changes
- ENVI header parameter names are case insensitive (converted to lower-case
after being read).
- `ImageArray` objects have additional `SpyFile` methods/attributes and
indexing behavior is now like `SpyFile`'s.
- An exception is now raised when attempting to open or save an image in
ENVI format with nonzero major or minor frame offsets (see issue 35).

Bug Fixes
- [Issue 27] ImageView.**str** failed if image did not have "bands" in
metadata.

- [Issue 19] Fixed handling of intereave keyword.
- [Issue 20] envi.save_image fails when interleave keyword is provided for
single-band images.
- [Issue 21] offset keyword has not effect in envi.create_image.
- [Issue 22] setup.py fails if numpy is not already installed.
- [Issue 24] save_rgb fails when format keyword is given.
- [Issue 25] view_cube fails in HypercubeWindow.load_textures.
- [Issue 26] Too few colors in view_cube side faces.

- [Issue 18] Missing import statements for pixel iterators.

New Features
- Adaptive Coherence/Cosine Estimator (ACE) target detector
- Pixel Purity Index (PPI)
- Adjustable linear color stretches (based on data limits or cumulative histogram)
- Ability to save ENVI Classification files (thanks to ohspite)
- `ImageView` class has `set_title` method

Changes
- `imshow` image displays use a linear 2% color stretch by default (can
override this in `spectral.settings`)
- Limited Python 3 compatibility (all functions except `view_cube` and `view_nd`) supported
- `get_rgb` handles bands with no variation (color set to min value)
- Modified `view_nd` to support change in PyOpenGL API

Bug Fixes
- [Issue 16] Incorrect handling of alternate file extensions in `envi.save_image`
- [Issue 11] Incorrect handling of unsigned byte data type in ENVI files
- [Issue 13] As of version 1.9, `numpy` no longer provides `oldnumeric` submodule