TeDa FITS Viewer

Observatory optimized FITS Images viewer

Key Features

• Flexible windows and widgets layout
• WCS support
• Radial Profile with gaussian fit - press R key at cursor position
  • Displays FWHM, RMS, and sky level
  • Shows area statistics (mean, std, range) in status bar
• Linear Profile - keyboard shortcuts for quick positioning:
  • H - horizontal line at cursor Y
  • V - vertical line at cursor X
  • D - diagonal line (45°), Shift+D - diagonal (135°)
  • Free hand line drawing with mouse
  • Shows profile statistics in status bar
• Real-time Statistics in status bar for Linear profile, Radial area, and whole Image
• Integrated file browser with directory tree and files list for quick navigation and opening
• Pinnable FITS header cards
• Scan mode: observes directory for changes and automatically opens new FITS
• Integrated ipython console with direct access to data and application
• Quick Help with keyboard shortcuts reference (press ? button or F1)

Installation

The safest and recommended way to install TeDa is to use pipx:

pipx install teda

Linux Desktop Integration

After installation on Linux, you can add TeDa to your application menu:

teda --install-desktop

This will:

• Install the application icon and desktop entry
• Make TeDa appear in your application menu
• Add TeDa to favorites panel (on GNOME/Ubuntu)

To remove the desktop entry:

teda --uninstall-desktop

Consult pipx documentation for pipx installation instructions.

Optional dependencies

To use ipython console the console extra should be specified. This extra installs ipython and qtconsole packages.

    pipx install teda[console]

For directory scanning functionality, the watchdog package should be installed, e.g.

    pipx install teda[watchdog]

Run

After installation, run TeDa from terminal:

teda

If the command is not found, ensure pipx binaries are in your PATH:

pipx ensurepath

On Linux, after running teda --install-desktop, you can also launch TeDa from your application menu.

Command line parameters

Open specific FITS file:

    teda /path/to/file.fits

Open with file explorer set to specific directory:

    teda /path/to/directory

View all command line options:

    teda --help

Useful options:

• --reset-layout - Reset window layout to defaults
• --reset-config - Reset all configuration (layout, sliders, pins, last file)
• -i or --ignore-settings - Start without loading saved configuration

Dynamic Scale and Color

The dynamic scale of the image, and color mapping can be adjusted form the Dynamic Scale panel. From menu: View/Dynamic Scale

Fits Header Cards Pinning

On the FITS Header panel, selected keys can be pinned to appear on the top ot the list. This can be done via context (right-click) menu.

The set of pinned keys is saved and preserved between sessions.

Keyboard Shortcuts

TeDa provides convenient keyboard shortcuts for fast workflow:

• R - Create radial profile at cursor position (with gaussian fit)
• H - Horizontal line profile at cursor Y
• V - Vertical line profile at cursor X
• D - Diagonal line profile (45° /)
• Shift+D - Diagonal line profile (135° )
• Del - Delete selected shape
• Ctrl+Drag - Adjust image brightness/contrast dynamically
• Ctrl+O - Open FITS file
• Ctrl+S - Save image view
• F1 - Show quick help with all shortcuts

Press the ? button in the toolbar for complete keyboard shortcuts reference.

Radial Profile

The Radial Profile button turns on the mode of selecting targets for the radial profile analysis. Make sure the radial profile panel is visible (View/Radial Profile). The shortcut for displaying radial profile of the star under cursor is the R key.

The centroid of the star is corrected within small (be precise!) radius using the bivariate gaussian fit.

Together with the pixel values, the radial profile presents 1D fit of "gaussian(r) + sky". This fit provides FWHM and sky level information on the chart.

Status bar displays area statistics (mean, median, std, min, max) for all pixels within the encircled area, calculated in background for performance.

Linear Profile

The Linear Profile tool (timeline icon in toolbar) allows analyzing intensity along a line. Quick keyboard shortcuts:

• H - Horizontal line at cursor Y position (full width)
• V - Vertical line at cursor X position (full height)
• D - Diagonal line at 45° (/) passing through cursor
• Shift+D - Diagonal line at 135° () passing through cursor

Or use the toolbar button to draw custom lines interactively.

The Linear Profile panel displays the intensity plot, and the status bar shows profile statistics (mean, std, value range) for all pixels along the line.

Integrated Python Console

In order to use integrated python console the console extra dependency group have to be installed

The console is available form menu View/Python Console

Predefined variables

The console has a number of predefined variables set:

• ax: WCSAxesSubplot main plotting axes.
• window: MainWindow main window
• data: numpy.ndarray current HDU data
• header: astropy.fits.Header current HDU header
• wcs: astropy.wcs.WCS the WCS transformer

Plotting

To plot directly on the console, run the following magic command %matplotlib inline.

When plotting on the main canvas, the result will appear after redrawing main figure by ax.figure.canvas.draw().

The example below, draws linear profile on the console and corresponding line on the main FITS display:

%matplotlib inline
import matplotlib.pyplot as plt
ax.plot([10,30], [10,10])
ax.figure.canvas.draw()
plt.plot(data[10,10:30])

Directory Scan

The Scan Toolbar (hidden by default) provides controls for the directory scanning mode.

This mode is intended to observe newly created FITS files in observatory.

After pressing Scan button, and choosing directory, TeDa Fits Viewer will load most recent FITS file from that directory, and keep watching the directory for changes. When new FITS file is added to directory, it will be loaded automatically.

User can pause scanning using Pause button. There is also auto pause feature, when active, any mouse movement in the main area pauses scanning for 5 seconds, avoiding FITS reload when working.

After un-pausing (manually or after idle 5 seconds when auto-pause) the newest FITS will be loaded if any new files appeared during the pause.

Directory scanning needs the watchdog extra dependency to be installed (see Installation above).

Directory Panel

The Directory Panel can be shown using menu command View-Directory view.

The Directory Panel is convenient files navigator. The panel has two views:

• Directory Tree
• Files List

User can collapse any of them using divider handle and use only remaining one. If the tree view is the only visible, it shows directories and files as well.

Development version install

TeDa uses poetry for development and packaging.

    git clone https://github.com/majkelx/teda.git
    cd teda
    poetry install

Bugs, remarks, greetings and contribution

Please use GitHub issues tracker and pull requests.

@2020-2025 AkondAstro for the Araucaria Project.