Files loading

Lxnstack can open several image file formats (including CR2 files) and video. To load the files you want to use, simply use the menu 'File' -> 'Open files' or click the button '+' in the section 'Frame list'. Then a dialog window will appear in which you can select the files to loaded.

All pictures ad videos must have the same size and number of channels (for example it is impossible to stack an RGB image with a grayscale image). If files that do not match this requirement are selected, they will be automatically rejected and a warning message with a list of this files will be shown.

Images in CR2 format have to be decoded before they can be used. The decoded images are saved in FITS format if possible[1] otherwise they are saved in NPY format. Depending on the setting of the application (see Preferences), the decoding process can be performed when the file is loaded for the first time or only when it is necessary.

If the an image contains EXIF metadata, the EXIF entries are stored in a file with .exif extension. The data stored in this file can be read using the pickle module[2] in python2

If the images are in RAW format (grayscale images containig raw data coming directly from the sensor) and they come from a sensor with a Bayer Matrix, then the "RAW mode" checkbox can be activated and the of Bayer matrix of the sensor can be selected.

Following, a portion of a RAW image (left) and the same portion in RAW Mode are shown.

One must be sure to select the right Bayer matrix (most DSLR and digital cameras use an RGGB pattern). Selecting a wrong Bayer pattern will lead to "strange" results like this:

EXAMPLE :

Suppose we want to load the file named file_name.cr2. The file will be decoded at loading time and the result will be saved as file_name.fits (or file_name.npy). The EXIF metadata are stored in a file named file_name.exif.

When we will load the file again the image data will be read form file_name.fits (or file_name.npy) and the EXIF informations will be read from file_name.exif, skipping the slow decoding process.

lxnstack © 2013 Maurizio D'Addona