Image Format#

Load two-dimensional astronomical images.

Overview#

The Image format is used for loading 2D astronomical imaging data, such as direct images from cameras and imagers.

Usage#

import jdaviz
jdaviz.show()

# Load an image
jdaviz.load('image.fits', format='Image')

Data Requirements#

The data should be a 2D array where:

  • Each pixel represents a spatial position on the sky

  • Pixel values represent flux/intensity measurements

Images can be in various coordinate systems and may include WCS (World Coordinate System) information for relating pixel positions to sky coordinates.

Supported File Formats#

  • FITS files with 2D image data

  • ASDF files with image data

  • JWST imaging data (i2d files)

  • HST imaging data

UI Access#

Data Association (Parent Dataset)#

When loading a file with multiple extensions (e.g. a FITS file with SCI, ERR, and DQ extensions), the importer can associate extensions with one another by setting up a parent-child relationship. An associated (child) data entry is nested under its parent in the data menu and is treated as a layer of the parent rather than as an independent image, e.g., child layers are not cycled through when blinking; only top-level (parent) data are blinked.

The Parent Dataset dropdown controls this behavior:

  • Auto (default): non-science extensions (e.g. ERR, DQ) are automatically associated with the matching science extension (SCI/DATA of the same version). The science parent may either be loaded in the same import or already present in the data collection from an earlier load (matched by an internal labeling mechanism), so loading an ERR extension later still associates it with a previously-loaded SCI extension.

  • None: no association is created, even when multiple extensions are imported. Each extension is loaded as an independent, top-level data entry.

  • A specific dataset: associate the new data as a child of the selected dataset.

ldr = jdaviz.loaders['file']
ldr.filename = 'image.fits'
ldr.format = 'Image'

# default 'Auto' associates ERR/DQ with their SCI extension
ldr.importer.parent = 'Auto'

# disable association entirely
ldr.importer.parent = 'None'

See Also#