Baseclass to map red, blue, green intensities into uint8 values. More...

Inheritance diagram for lsst.afw.display.rgb.Mapping:

Public Member Functions
def	__init__ (self, minimum=None, image=None)
	Create a mapping. More...

def	makeRgbImage (self, imageR=None, imageG=None, imageB=None, xSize=None, ySize=None, rescaleFactor=None)
	Convert 3 arrays, imageR, imageG, and imageB into a numpy RGB image. More...

def	intensity (self, imageR, imageG, imageB)
	Return the total intensity from the red, blue, and green intensities. More...

def	mapIntensityToUint8 (self, intensity)

Public Attributes
	minimum

Detailed Description

Baseclass to map red, blue, green intensities into uint8 values.

Definition at line 65 of file rgb.py.

Constructor & Destructor Documentation

◆ init()

def lsst.afw.display.rgb.Mapping.__init__	(	self,
		minimum = `None`,
		image = `None`
	)

Create a mapping.

Parameters

minimum	Intensity that should be mapped to black (a scalar or array for R, G, B)
image	The image to be used to calculate the mapping.

If provided, also the default for makeRgbImage()

Definition at line 68 of file rgb.py.

     def __init__(self, minimum=None, image=None):
         """!Create a mapping
         @param minimum  Intensity that should be mapped to black (a scalar or array for R, G, B)
         @param image The image to be used to calculate the mapping.
 
         If provided, also the default for makeRgbImage()
         """
         self._uint8Max = float(np.iinfo(np.uint8).max)
 
         try:
             len(minimum)
         except TypeError:
             minimum = 3*[minimum]
         assert len(minimum) == 3, "Please provide 1 or 3 values for minimum"
 
         self.minimum = minimum
         self._image = image
 

Member Function Documentation

◆ intensity()

def lsst.afw.display.rgb.Mapping.intensity	(	self,
		imageR,
		imageG,
		imageB
	)

Return the total intensity from the red, blue, and green intensities.

This is a naive computation, and may be overridden by subclasses

Definition at line 143 of file rgb.py.

     def intensity(self, imageR, imageG, imageB):
         """!Return the total intensity from the red, blue, and green intensities
 
         This is a naive computation, and may be overridden by subclasses
         """
         return computeIntensity(imageR, imageG, imageB)
 

◆ makeRgbImage()

def lsst.afw.display.rgb.Mapping.makeRgbImage	(	self,
		imageR = `None`,
		imageG = `None`,
		imageB = `None`,
		xSize = `None`,
		ySize = `None`,
		rescaleFactor = `None`
	)

Convert 3 arrays, imageR, imageG, and imageB into a numpy RGB image.

Parameters

imageR	Image to map to red (if None, use the image passed to the ctor)
imageG	Image to map to green (if None, use imageR)
imageB	Image to map to blue (if None, use imageR)
xSize	Desired width of RGB image (or None). If ySize is None, preserve aspect ratio
ySize	Desired height of RGB image (or None)
rescaleFactor	Make size of output image rescaleFactor*size of the input image (or None)

N.b. images may be afwImage.Images or numpy arrays

Definition at line 87 of file rgb.py.

                      xSize=None, ySize=None, rescaleFactor=None):
         """!Convert 3 arrays, imageR, imageG, and imageB into a numpy RGB image
         @param imageR Image to map to red (if None, use the image passed to the ctor)
         @param imageG Image to map to green (if None, use imageR)
         @param imageB Image to map to blue (if None, use imageR)
         @param xSize  Desired width of RGB image (or None).  If ySize is None, preserve aspect ratio
         @param ySize  Desired height of RGB image (or None)
         @param rescaleFactor Make size of output image rescaleFactor*size of the input image (or None)
 
         N.b. images may be afwImage.Images or numpy arrays
         """
         if imageR is None:
             if self._image is None:
                 raise RuntimeError(
                     "You must provide an image (or pass one to the constructor)")
             imageR = self._image
 
         if imageG is None:
             imageG = imageR
         if imageB is None:
             imageB = imageR
 
         imageRGB = [imageR, imageG, imageB]
         for i, c in enumerate(imageRGB):
             if hasattr(c, "getImage"):
                 c = imageRGB[i] = c.getImage()
             if hasattr(c, "getArray"):
                 imageRGB[i] = c.getArray()
 
         if xSize is not None or ySize is not None:
             assert rescaleFactor is None, "You may not specify a size and rescaleFactor"
             h, w = imageRGB[0].shape
             if ySize is None:
                 ySize = int(xSize*h/float(w) + 0.5)
             elif xSize is None:
                 xSize = int(ySize*w/float(h) + 0.5)
 
             size = (ySize, xSize)  # n.b. y, x order for scipy
         elif rescaleFactor is not None:
             size = float(rescaleFactor)  # an int is intepreted as a percentage
         else:
             size = None
 
         if size is not None:
             try:
                 import scipy.misc
             except ImportError as e:
                 raise RuntimeError(
                     "Unable to rescale as scipy.misc is unavailable: %s" % e)
 
             for i, im in enumerate(imageRGB):
                 imageRGB[i] = scipy.misc.imresize(
                     im, size, interp='bilinear', mode='F')
 
         return np.dstack(self._convertImagesToUint8(*imageRGB)).astype(np.uint8)
 

◆ mapIntensityToUint8()

def lsst.afw.display.rgb.Mapping.mapIntensityToUint8	(	self,
		intensity
	)

Map an intensity into the range of a uint8, [0, 255] (but not converted to uint8)

Definition at line 150 of file rgb.py.

     def mapIntensityToUint8(self, intensity):
         """Map an intensity into the range of a uint8, [0, 255] (but not converted to uint8)"""
         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._uint8Max, intensity, self._uint8Max))
 

Member Data Documentation

◆ minimum

lsst.afw.display.rgb.Mapping.minimum

Definition at line 83 of file rgb.py.

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

/j/snowflake/release/lsstsw/stack/Linux64/afw/16.0-14-gb4f0cd2fa/python/lsst/afw/display/rgb.py

Public Member Functions

Public Attributes