A mapping for an asinh stretch (preserving colours independent of brightness).
x = asinh(Q (I - minimum)/stretch)/Q
This reduces to a linear stretch if Q == 0
See https://ui.adsabs.harvard.edu/abs/2004PASP..116..133L
Parameters
----------
minimum : float
Intensity that should be mapped to black (a scalar or array for R, G, B).
stretch : float
The linear stretch of the image.
Q : float
The asinh softening parameter.
Definition at line 189 of file _fallback_asinhmapping.py.
| lsst.pipe.tasks._fallback_asinhmapping.Mapping.intensity |
( |
| self, |
|
|
| image_r, |
|
|
| image_g, |
|
|
| image_b ) |
|
inherited |
Return the total intensity from the red, blue, and green intensities.
This is a naive computation, and may be overridden by subclasses.
Parameters
----------
image_r : ndarray
Intensity of image to be mapped to red; or total intensity if
``image_g`` and ``image_b`` are None.
image_g : ndarray, optional
Intensity of image to be mapped to green.
image_b : ndarray, optional
Intensity of image to be mapped to blue.
Returns
-------
intensity : ndarray
Total intensity from the red, blue and green intensities, or
``image_r`` if green and blue images are not provided.
Definition at line 60 of file _fallback_asinhmapping.py.
| lsst.pipe.tasks._fallback_asinhmapping.Mapping.make_rgb_image |
( |
| self, |
|
|
| image_r, |
|
|
| image_g, |
|
|
| image_b ) |
|
inherited |
Convert 3 arrays, image_r, image_g, and image_b into an 8-bit RGB image.
Parameters
----------
image_r : ndarray
Image to map to red.
image_g : ndarray
Image to map to green.
image_b : ndarray
Image to map to blue.
Returns
-------
RGBimage : ndarray
RGB (integer, 8-bits per channel) color image as an NxNx3 numpy array.
Definition at line 32 of file _fallback_asinhmapping.py.
| lsst.pipe.tasks._fallback_asinhmapping.AsinhMapping.map_intensity_to_uint8 |
( |
| self, |
|
|
| I ) |
Return an array which, when multiplied by an image, returns that image
mapped to the range of a uint8, [0, 255] (but not converted to uint8).
The intensity is assumed to have had minimum subtracted (as that can be
done per-band).
Parameters
----------
I : ndarray
Intensity to be mapped.
Returns
-------
mapped_I : ndarray
``I`` mapped to uint8
Reimplemented from lsst.pipe.tasks._fallback_asinhmapping.Mapping.
Definition at line 222 of file _fallback_asinhmapping.py.
1.13.2