lsst.afw.display.rgb._rgbContinued.LinearMapping Class Reference

Inheritance diagram for lsst.afw.display.rgb._rgbContinued.LinearMapping:

Public Member Functions
	__init__ (self, minimum=None, maximum=None, image=None)
	mapIntensityToUint8 (self, intensity)

Public Attributes
	maximum

Protected Attributes
	_range

Detailed Description

A linear map of red, blue, green intensities into uint8 values

Parameters
----------
minimum : `float` or sequence of `float`
    Intensity that should be mapped to black. If an array, has three
    elements for R, G, B.
maximum : `float`
    Intensity that should be mapped to white
image
    Image to estimate minimum/maximum if not explicitly set

Definition at line 213 of file _rgbContinued.py.

Constructor & Destructor Documentation

__init__()

lsst.afw.display.rgb._rgbContinued.LinearMapping.__init__	(		self,
			minimum = None,
			maximum = None,
			image = None )

Reimplemented from lsst.afw.display.rgb._rgbContinued.Mapping.

Reimplemented in lsst.afw.display.rgb._rgbContinued.ZScaleMapping.

Definition at line 227 of file _rgbContinued.py.

    def __init__(self, minimum=None, maximum=None, image=None):
        if minimum is None or maximum is None:
            assert image is not None, "You must provide an image if you don't set both minimum and maximum"
 
            stats = afwMath.makeStatistics(image, afwMath.MIN | afwMath.MAX)
            if minimum is None:
                minimum = stats.getValue(afwMath.MIN)
            if maximum is None:
                maximum = stats.getValue(afwMath.MAX)
 
        Mapping.__init__(self, minimum, image)
        self.maximum = maximum
 
        if maximum is None:
            self._range = None
        else:
            assert maximum - minimum != 0, "minimum and maximum values must not be equal"
            self._range = float(maximum - minimum)
 

Member Function Documentation

mapIntensityToUint8()

lsst.afw.display.rgb._rgbContinued.LinearMapping.mapIntensityToUint8	(		self,
			intensity )

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)

Reimplemented from lsst.afw.display.rgb._rgbContinued.Mapping.

Definition at line 246 of file _rgbContinued.py.

    def mapIntensityToUint8(self, intensity):
        """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)
        """
        with np.errstate(invalid='ignore', divide='ignore'):  # n.b. np.where can't and doesn't short-circuit
            return np.where(intensity <= 0, 0,
                            np.where(intensity >= self._range,
                                     self._uint8Max/intensity, self._uint8Max/self._range))
 
 

Member Data Documentation

_range

lsst.afw.display.rgb._rgbContinued.LinearMapping._range

protected

Definition at line 241 of file _rgbContinued.py.

maximum

lsst.afw.display.rgb._rgbContinued.LinearMapping.maximum

Definition at line 238 of file _rgbContinued.py.

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The documentation for this class was generated from the following file:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-9.0.0/Linux64/afw/gef2f8181fd+3031e3cf99/python/lsst/afw/display/rgb/_rgbContinued.py