Package gavo :: Package utils :: Module imgtools

Module imgtools

Some miscellaneous helpers for making images and such.

As this may turn into a fairly expensive import, this should *not* be imported by utils.__init__. Hence, none of these functions are in gavo.api or gavo.utils.

Functions

jpegFromNumpyArray(pixels, gamma=0.25)
returns a normalized JPEG for numpy pixels.

source code

colorJpegFromNumpyArrays(rPix, gPix, bPix, gamma=0.25)
as jpegFromNumpyArray, except a color jpeg is built from red, green, and blue pixels.

source code

scaleNumpyArray(arr, destSize)
returns the numpy array arr scaled down to approximately destSize.

source code

getScaledPNG(srcFile, newWidth)
returns a PNG string that is a scaled version of an image in srcFile.

source code

Variables
	__package__ = `'gavo.utils'`

Function Details

jpegFromNumpyArray(pixels, gamma=0.25)

source code

returns a normalized JPEG for numpy pixels.

pixels is assumed to come from FITS arrays, which are flipped wrt to jpeg coordinates, which is why we're flipping here.

The normalized intensities are scaled by v^gamma; we believe the default helps with many astronomical images

getScaledPNG(srcFile, newWidth)

source code

returns a PNG string that is a scaled version of an image in srcFile.

srcFile must correspond to something that PIL can read. Since scaling really sucks for non-RGB images, we unconditionally convert whatever we get to 3-band RGB.