Tenmon help

Tenmon is intended primarily for viewing astro photos and images. It supports the following formats:

FITS 8, 16 bit integer and 32 bit float
XISF 8, 16 bit integer and 32 bit float
JPEG and PNG images

Main windows

The main window shows the currently loaded image. On the left is the Image info panel which displays details about the loaded image. The File system panel shows other images in the same directory as the loaded image. At the top is the main menu and below that is the Stretch panel containing various options for auto-stretching linear image data.

All panels in the interface can be moved around and/or closed. Any closed or non-visible panel can be re-opened through the Docks menu at the top.

Opening and saving images

To load an image select File->Open and choose the file. After a file is loaded, it becomes visible in the main image panel, and the File system panel will show the other images in the same directory.

The loaded image can be exported to a different format with File->Save as. Any of the formats JPEG, PNG FITS and XISF can be selected. In the case of saving JPEG or PNG, the stretch function is applied to the saved image. FITS and XISF are saved/converted without applying the stretch. To open an image, you can also drag and drop it to main window.

View

The View menu has options to control the size and scale of displayed images:

Zoom In and Zoom Out magnify and shrink the image. The mouse wheel can be also used to zoom freely.
Best fit auto-zooms the image to fit the current size of the window.
100% will zoom to 1:1 scale.
Fullscreen enlarges the main window to the whole screen.
Thumbnails will display small thumbnails for all images in the current directory.

Stretch toolbar

This panel changes how images are displayed.

Starting on the left, there is slider scale with three adjustable points to manually control the stretch.

black point - all pixels with lower value (darker) than this setting will be clipped black
mid point - defines the value to be stretched to 50% intensity
white point - all pixels with higher value (brighter) than this will be clipped white

Following the slider are 5 buttons for automatic stretching:

Auto Stretch automatically apply black and mid points to render the image with optimal brightness.
Reset reset three values for black, mid and white point to default.
Invert invert colors to display the image as negative.
Super pixel CFA average 2x2 pixels into one (suitable for images from colour camera).
Apply Auto stretch on load toggle automatically applying Autostretch for each image when loaded.

Marking images

Images can be marked in the Select menu. To show a list of only the marked images, use Select->Show marked. This dialog can be useful to clear marks from images. Marked images show a * character in the title bar of the main window. Marked images can be copied or moved to a selected directory with File->Copy/Move marked files. After copying or moving, the list of marked files is cleared. The list of marked files will be remembered after quitting the program.

Database of FITS/XISF files

Tenmon can scan a directory of FITS/XISF files and index metadata from FITS headers into it's internal database. This allows searching and sorting images based on that metadata.

To populate the database, select a directory of FITS/XISF files with File->Index directory. After the selected directory is searched, metadata parsed from the images will be stored in the database. To refresh the database, run File->Reindex. This will update any changed metadata and remove any record of deleted files. To index new files, simply run Index directory again.

The database is viewed through a panel which is not visible in the default layout. To add the database panel to the view, toggle Docks->FITS/XISF database. Once visible, database panel shows the database as a table with a column for each property. Below the table is button to select which columns/properties are displayed.

Also at the bottom of the database panel are three combo boxes and text inputs used for filtering. Select the property to filter on with the combo box and in the adjacent text box enter a string to search for in that property.

Wildcards:

% (percent) is a wildcard representing zero or more of any characters.
_ (underscore) is a wildcard for exactly one of any character.
Without wildcard characters, the exact string must match.

This example filters for files where: "Bias" is in the file name, the OBJECT property is "M_42" (where the underscore can be any single character), and the DATE property begins with "2022".

PS: Kanji in icon means astronomy in Japanese