Documentation
Controls
Shortcuts
Shortcut | Description |
---|---|
Ctrl + O | Open Spectral image (ENVI file format). |
Ctrl + S | Save image: |
- as HDR RGB image (exr) if opened image is spectral. | |
- as LDR RGB image (png, jpeg …) if opened image is not spectral. | |
Ctrl + H | Show Help. |
R | Reset view parameters (zoom, rotation, auto tonemapping). |
F5 | Refresh (reopen current file, doesn’t work with a PNG collection). |
Spectrum graph
Spectrum selection
Control | Description |
---|---|
Left click | Select one wavelength. |
Left click + drag | Select a range of wavelengths. |
Left click (around start or end bar of selection) + drag | Move start or end of selection. |
Right click | Reset selection to fully displayed spectrum. |
Mouse wheel up | Extend selection on both sides. |
Mouse wheel down | Shrink selection on both sides. |
Middle click + drag OR Ctrl + Left click + drag (inside selection) | Move selection. |
Left Arrow | Move selection to the left. |
Right Arrow | Move selection to the right. |
Mouse move | Select nearest point on graph and display its value. |
Spectrum X-Axis (Wavelength)
To make this shortcuts work, you need to uncheck the “Auto rescale wavelength” in the “Display” groupbox.
Shortcut | Description |
---|---|
Shift + Mouse wheel up | Extend wavelength range (x-axis) on both sides. |
Shift + Mouse wheel down | Shrink wavelength range (x-axis) on both sides. |
Shift + Middle click + drag OR Ctrl + Shift + Left click + drag: | Move wavelength range (x-axis). |
Shift + Left Arrow | Move wavelength range (x-axis) to the right. |
Shift + Right Arrow | Move wavelength range (x-axis) to the left. |
Image widget
Control | Description |
---|---|
Mouse move | Change selected pixel (if not locked). |
Left click | Select and Lock pixel. |
Right click | Unlock pixel and select. |
Mouse wheel up/down | Zoom In/Out. |
Middle click + drag OR Ctrl + Left click | Move image. |
Drag and drop a .hdr file (ENVI format) | Open as ENVI file. |
Supported file formats
Spectral images
Three types of spectral images are supported:
- PNG collections.
- ENVI files.
- ART raw files.
PNG collection
A png collection can be opened using File
-> Open folder
. Each PNG image should be a gray image representing a dedicated wavelength. All PNGs must be in the same folder and the folder should not contain any other PNGs.
All PNGs filename must end with _X
where X
is a positive number indicating in which order the PNGs should be used. The GUI provides a way to specify the mapping between the png number and the wavelengths.
An example of such image collection can be found at: http://www.cs.columbia.edu/CAVE/databases/multispectral/
ENVI file format
The supported ENVI file format is described here: http://www.harrisgeospatial.com/docs/ENVIHeaderFiles.html. It consists of a set of two files: a header (.hdr) and raw data (.raw).
Both files should have the same name (except for the extension) and placed in the same folder.
Some examples can be found here: http://icvl.cs.bgu.ac.il/hyperspectral/
ART Raw file format
Spectral Viewer supports reading of unpolarised spectral ART Raw format. This format is used by ART, The Advanced Rendering Toolkit physically based renderer https://cgg.mff.cuni.cz/ART/.
RGB images
Some HDR and LDR RGB formats are supported: all the formats supported by Qt5, with the addition
- OpenEXR format.
- PFM format.
- Ward’s HDR format.
When a RGB image is opened, the Spectrum graph and Spectrum parameters panels automatically disappear.
User preferences
Some parameters are automatically saved and retrieved when the viewer gets re-opened:
- Spectrum graph point size
- Last used folder
- Spectrum graph/parameters GUI layout
- Application window size and position
- Image tools/infos layout