Display

class lsst.afw.display.Display(frame=None, backend=None, *args, **kwargs)

Bases: object

Create an object able to display images and overplot glyphs

Parameters:

frame

An identifier for the display

backendstr

The backend to use (defaults to value set by setDefaultBackend())

*args

Arguments to pass to the backend

**kwargs

Arguments to pass to the backend

Attributes Summary

verbose

The backend's verbosity

Methods Summary

Buffering()	Return a class intended to be used with python's with statement
close()
delAllDisplays()	Delete and close all known displays
dot(symb, c, r[, size, ctype, origin])	Draw a symbol onto the specified display frame
erase()	Erase the specified display frame
flush()	Flush the buffers
getActiveCallbackKeys([onlyActive])	Return all callback keys
getDefaultBackend()
getDefaultFrame()	Get the default frame for display
getDisplay([frame, backend, create, verbose])	Return a specific Display, creating it if need be
getMaskPlaneColor([name])	Return the color associated with the specified mask plane name
getMaskTransparency([name])	Return the current display's mask transparency
incrDefaultFrame()	Increment the default frame for display
interact()	Enter an interactive loop, listening for key presses in display and firing callbacks.
line(points[, origin, symbs, ctype, size])	Draw a set of symbols or connect points
maskColorGenerator([omitBW])	A generator for "standard" colors
mtv(data[, title, wcs])	Display an image on a display, with semi-transparent masks overlaid, if available.
pan([colc, rowc, origin])	Pan to a location
scale(algorithm, min[, max, unit])	Set the range of the scaling from DN in the image to the image display
setCallback(k[, func, noRaise])	Set the callback for a key
setDefaultBackend(backend)
setDefaultFrame([frame])	Set the default frame for display
setDefaultImageColormap(cmap)	Set the default colormap for images
setDefaultMaskPlaneColor([name, color])	Set the default mapping from mask plane names to colors
setDefaultMaskTransparency([...])
setImageColormap(cmap)	Set the colormap to use for images
setMaskPlaneColor(name[, color])	Request that mask plane name be displayed as color
setMaskTransparency([transparency, name])	Specify display's mask transparency (percent); or None to not set it when loading masks
show()	Uniconify and Raise display.
zoom([zoomfac, colc, rowc, origin])	Zoom frame by specified amount, optionally panning also

Attributes Documentation

verbose

The backend’s verbosity

Methods Documentation

Buffering()

Return a class intended to be used with python’s with statement

Examples

with display.Buffering():
    display.dot("+", xc, yc)

close()

static delAllDisplays()

Delete and close all known displays

dot(symb, c, r, size=2, ctype=None, origin=<ImageOrigin.PARENT: 0>, *args, **kwargs)

Draw a symbol onto the specified display frame

Parameters:

symb

Possible values are:

"+"

Draw a +

"x"

Draw an x

"*"

Draw a *

"o"

Draw a circle

"@:Mxx,Mxy,Myy"

Draw an ellipse with moments (Mxx, Mxy, Myy) (argument size is ignored)

lsst.afw.geom.ellipses.BaseCore

Draw the ellipse (argument size is ignored). N.b. objects derived from BaseCore include Axes and Quadrupole.

Any other value

Interpreted as a string to be drawn.

c, r

The column and row where the symbol is drawn [0-based coordinates]

sizeint

Size of symbol, in pixels

ctypestr

The desired color, either e.g. lsst.afw.display.RED or a color name known to X11

originlsst.afw.image.ImageOrigin

Coordinate system for the given positions.

*args

Extra arguments to backend

**kwargs

Extra keyword arguments to backend

erase()

Erase the specified display frame

flush()

Flush the buffers

getActiveCallbackKeys(onlyActive=True)

Return all callback keys

Parameters:

onlyActivebool

If True only return keys that do something

static getDefaultBackend()

static getDefaultFrame()

Get the default frame for display

static getDisplay(frame=None, backend=None, create=True, verbose=False, *args, **kwargs)

Return a specific Display, creating it if need be

Parameters:

frame

The desired frame (None => use defaultFrame (see setDefaultFrame))

backendstr

create the specified frame using this backend (or the default if None) if it doesn’t already exist. If backend == "", it’s an error to specify a non-existent frame.

createbool

create the display if it doesn’t already exist.

verbosebool

Allow backend to be chatty

*args

arguments passed to Display constructor

**kwargs

keyword arguments passed to Display constructor

getMaskPlaneColor(name=None)

Return the color associated with the specified mask plane name

Parameters:

namestr

Desired mask plane; if None, return entire dict

getMaskTransparency(name=None)

Return the current display’s mask transparency

static incrDefaultFrame()

Increment the default frame for display

interact()

Enter an interactive loop, listening for key presses in display and firing callbacks.

Exit with q, CR, ESC, or any other callback function that returns a True value.

line(points, origin=<ImageOrigin.PARENT: 0>, symbs=False, ctype=None, size=0.5)

Draw a set of symbols or connect points

Parameters:

pointslist

a list of (col, row)

originlsst.afw.image.ImageOrigin

Coordinate system for the given positions.

symbsbool or sequence

If symbs is True, draw points at the specified points using the desired symbol, otherwise connect the dots.

If symbs supports indexing (which includes a string – caveat emptor) the elements are used to label the points

ctypestr

ctype is the name of a color (e.g. ‘red’)

sizefloat

maskColorGenerator(omitBW=True)

A generator for “standard” colors

Parameters:

omitBWbool

Don’t include BLACK and WHITE

Examples

colorGenerator = interface.maskColorGenerator(omitBW=True)
for p in planeList:
    print(p, next(colorGenerator))

mtv(data, title='', wcs=None)

Display an image on a display, with semi-transparent masks overlaid, if available.

Parameters:

datalsst.afw.image.Exposure or lsst.afw.image.MaskedImage or lsst.afw.image.Image

Image to display.

titlestr, optional

Title for the display window.

wcslsst.afw.geom.SkyWcs, optional

World Coordinate System to align an MaskedImage or Image to; raise an exception if data is an Exposure.

Raises:

RuntimeError

Raised if an Exposure is passed with a non-None wcs when the wcs kwarg is also non-None.

TypeError

Raised if data is an incompatible type.

Notes

Historical note: the name “mtv” comes from Jim Gunn’s forth imageprocessing system, Mirella (named after Mirella Freni); The “m” stands for Mirella.

pan(colc=None, rowc=None, origin=<ImageOrigin.PARENT: 0>)

Pan to a location

Parameters:

colc, rowc

the coordinates to pan to

originlsst.afw.image.ImageOrigin

Coordinate system for the given positions.

See also

Display.zoom

scale(algorithm, min, max=None, unit=None, *args, **kwargs)

Set the range of the scaling from DN in the image to the image display

Parameters:

algorithmstr

Desired scaling (e.g. “linear” or “asinh”)

min

Minimum value, or “minmax” or “zscale”

max

Maximum value (must be None for minmax|zscale)

unit

Units for min and max (e.g. Percent, Absolute, Sigma; None if min==minmax|zscale)

*args

Optional arguments to the backend

**kwargs

Optional keyword arguments to the backend

setCallback(k, func=None, noRaise=False)

Set the callback for a key

Parameters:

k

The key to assign the callback to

funccallable

The callback assigned to k

noRaisebool

Returns:

oldFunccallable

The callback previously assigned to k.

static setDefaultBackend(backend)

static setDefaultFrame(frame=0)

Set the default frame for display

static setDefaultImageColormap(cmap)

Set the default colormap for images

Parameters:

cmapstr

Name of colormap, as interpreted by the backend

Notes

The only colormaps that all backends are required to honor (if they pay any attention to setImageColormap) are “gray” and “grey”

static setDefaultMaskPlaneColor(name=None, color=None)

Set the default mapping from mask plane names to colors

Parameters:

namestr or dict

name of mask plane, or a dict mapping names to colors If name is None, use the hard-coded default dictionary

color

Desired color, or None if name is a dict

static setDefaultMaskTransparency(maskPlaneTransparency={})

setImageColormap(cmap)

Set the colormap to use for images

Parameters:

cmapstr

Name of colormap, as interpreted by the backend

Notes

The only colormaps that all backends are required to honor (if they pay any attention to setImageColormap) are “gray” and “grey”

setMaskPlaneColor(name, color=None)

Request that mask plane name be displayed as color

Parameters:

namestr or dict

Name of mask plane or a dictionary of name -> colorName

colorstr

The name of the color to use (must be None if name is a dict)

Colors may be specified as any X11-compliant string (e.g. "orchid"), or by one of the following constants in lsst.afw.display : BLACK, WHITE, RED, BLUE, GREEN, CYAN, MAGENTA, YELLOW.

If the color is “ignore” (or IGNORE) then that mask plane is not displayed

The advantage of using the symbolic names is that the python interpreter can detect typos.

setMaskTransparency(transparency=None, name=None)

Specify display’s mask transparency (percent); or None to not set it when loading masks

show()

Uniconify and Raise display.

Notes

Throws an exception if frame doesn’t exit

zoom(zoomfac=None, colc=None, rowc=None, origin=<ImageOrigin.PARENT: 0>)

Zoom frame by specified amount, optionally panning also