The main interface opens with a video/image display and some tabbed control and options pages to the right where the user can input various settings and perform imaging actions. On the main control tab there are buttons for the following controls:
- Start live video display
- Stop live video display (the last captured frame will still show in the display)
- Open device dialog to set select imaging device, set frame rate and set image format
- Open settings dialog to control an exposure tab with brightness, contrast, gain, exposure, auto reference and auto max exposure value as well as an additional image tab for sharpness, gamma and denoise
- Save a sequence of images equal to the number in the adjacent box, these images will be saved to file via a save file dialog once all images are captures where the user can choose a file name and all images will be sequentially numbered when saved
- Save a single image
- Save and AVI video clip by means of a dialog where the user can choose various options regarding codecs
In addition there are informational displays to indicate the following values:
- Calculated solar zenith angle (corrected for parallax)
- Calculated solar altitude
- UTC time
- Local time
- Camera serial number
- The auto capture mode when selected automatically captures images between dusk and dawn by setting the exposure to the user required length and saves them to the user specified root folder. Each day at noon a new folder will be created and each nights images will be automatically put into their own folders for easy identification and will be sequentially numbered.
- The folder button opens a folder browser dialog allowing the user to select a root folder where they want to save all of their images.
- The solar altitude setting allows the user to put in the altitude in degrees at which they want to declare the sun to be at twilight. Normal astronomical dusk can be considered between -12 and 18 degrees.
- The interval setting declares how often (in minutes) the user wants to save an image to disk.
The auto capture function will only be active when the sun is below the altitude set by the user and when the sun rises above this limit the system will automatically stop capturing until the sun drops below the set limit again.
- Checking the Upload to FTP box will enable the system to automatically upload images to the users FTP server for remote web viewing or any other purpose they wish.
- The large box is for the user to type in the address of their FTP server along with the file path and file name they require the image to be assigned.
- The left box is provided for the user to enter their FTP server username.
- The right box is provided for the user to enter their FTP password.
- The interval setting allows the user to select an interval in minutes for the system to upload images to the FTP server. It will automatically overwrite the old image on the FTP server so that whenever the webpage is refreshed it will show the latest image.
Following this there is an options tab for various program and user settings:
The two location boxes allow the user to set their local position, Latitude and Longitude in degrees. The degrees are entered in their decimal format and are used to allow the software to correctly calculate the suns position for automatic operation.
Disk Space Management:
- Checking this option enables the system to automatically clean up old files from the auto capture root folder to conserve disk space. When active it will run a daily timer which will check every 24 hours and remove any files older than the user specified limit.
- The drop down box allows the user to select length of time in day to keep files before deleting.
As this system is meant for disk space management the files are irrecoverably destroyed and cannot be retrieved from the recycle bin.
Overlay Info is a newly added feature and one that may be developed further in the future. It is enabled by default when the progran starts but can be disabled from here and generates 2 different overlays onto both the display and the saved images. The first is a time tag with a date/time string representing the users local system time for easy identification of when events happened and hard coding that into the images. The second is a really simple set of compass points at top, bottom, left and right of the image with the North being at the bottom and south at the top due to the camera pointing directly upwards.
There are in addition two colour options for the compass overlay. One being a red selected by the color button and the other being a “best fit” mode which determines the best rendering depending on what the background image is displaying; this is especially useful for monochrome cameras where the image may be too bright in one spot due to the moon or brightly lit clouds during the day so it will be displayed dark while others may be displayed in a lighter shade. Although visually on the screen the user will see the compass overlay in red any saved images will not have a red overlay due to the image buffer being set to save the images in a greyscale format when using a monochrome camera
The Display/Processing tab has options modification of the live display and image processing.
The sensor format allows the user to select the appropriate resolution of their sensor which in turn sets the correct aspect ration of the live display to match the sensor and prevents the displayed image from appearing distorted.
Dark frame subtraction can be carried out on auto capture images as well as images uploaded to FTP server and will only subtract dark images when the sun is below the solar altitude limit. This is currently supported only in Y800 (8 bit greyscale) format with support for 8 bit color formats to follow in a later release. As with normal imaging the user will need to ensure that the dark file is of the same exposure as their maximum auto exposure length and as the dark subtraction is only done at astronomical twilight then the auto exposure should always have reached it’s maximum. The only issue would be if the user decided to use exposures longer than 60 seconds which would be highly unlikely due to the turning of the earth causing star trails at exposures any longer than this.
- Dark subtract auto cap enables the system to automatically subtract a master dark frame from the image in the cameras image buffer before saving it to disk. Although this option is present it is recommended that if looking for pure raw data then this should not be used as the data is altered before being written to disk and the original data will be lost. A better procedure would be to keep the raw data and dark subtract copies of that raw data at a later date.
- Dark subtract FTP is more what the feature was designed for originally as this allows the user to remove dark frames from the images that are being uploaded for public viewing where a cosmetic appearance is more important.
- The dark file button opens a file browser dialog which allows the user to select a master dark file to used for dark subtraction. The user will need to create the master dark in third party software from a set of dark images they can capture with the capture image sequence function.
A couple of basic filters have also been added for convenience:
- The denoise filter is used to smooth out grainy looking images but should not be used during long exposure mode as it does the smoothing in a similar fashion to popular photo editing unsharp masks and averages together a user selected number of frames. During daylight hours on short exposures that is gine but long exposures will appear blurred.
- The Rotate/Flip filter allows the user to rotate the image in 90° steps or to flip the image around either the horizontal or vertical axis so that the image can be aligned to best suit the camera orientation with respect to the sky and the users preference.
The Process stills button opens up a new dialog window which allows the user to select a folder containing a collection of still images and to quickly process these into a time lapse video which will be output to the users selected location in .mp4 format with the h264 codec. The user can select the desired quality of the output to enable smaller video file size for quick review of an evenings data or to limit file size for uploading.