PEAAnuts main window: Stream analysisThe PEAAnuts module plugs itself into FireCaptures (FC) interface. It retrieves the frames which FC has read out from the camera, copies them and prepares them for further processing and evaluation. So the original frame data are not compromised, and the plugin can be active during recording, too.If a planet or any confined shape can be detected in the ROI, it is extracted and shown in the PEAAnuts stream view. The default detection threshhold setting suffices for usual nightime scenes, in special circumstances, manual adjustment might be necessary. Below the image window, a cross section intensity plot of the actual ROI is plotted. By default, the cross section is centered vertically w.r. to the detected planet. The bottom part of the window shows some analysis data derived from the intensity plot, which can be heplful for focusing. The plugin is only active if a sufficiently small ROI is selected in FC. Operating in full-frame mode would demand a lot of calculation time, at least with todays big camera chips. Remember that the plugin is explicitely developed for planetary imaging. For full frame deep sky imaging, there already exist a lost of highly optimized tools. When the frame size exceeds the limit (default 1000 pixels, adjustable in the 'System options' dialog), the plugin automatically enters a standby mode, and activates itself again when the ROI size / frame size drops again. You may experience this for example when shortly switching FC to max. screen preview in order to reposition the planet on the screen, and then selecting a new ROI again. The images extracted from the ROI are always quadratic in shape. The PEAAnuts stream view image size must be adjusted manually via the drop down list in the first button row in the top section. Optionally, auto-scaling can be activated, which squeezes or expands the extracted planet to fit into the actual preview image size. Note that scaling usually has a negative influence on image quality and thus should be used with caution. The rest of the PEAAnuts main window is filled by several buttons which lead to parameter dialogs and administration stuff. Stream analysis and preparation basicsThe plugin does some minimal pre-stacking which reduces noise and provides a better base for the following evaluation. The prestacking can be adjusted with two drow down lists at the bottom left of the window. Note that there are two stages of prestacking. The leftmost setting, 'PA', specifies the number of frames for preaddition. When live stacking is active, these preadded frames are sent to the stacking module, so it is a good practice to keep the PA setting low, e.g. 2, 3 or maybe 4 in usual circumstances. The better the seeing, the higher the number can be.For the stream preview and analysis, some more averaging is helpful. With the second drop down list 'SPV', a multiplier can be chosen. This number specifies how much of the preadded frames will be accumulated for the stream preview. So the stream preview is smoothed further than the frames which are internally used for live stacking. Example: PA = 2 and SPV = 3 means, always 2 frames will be accumulated before sending this prestack to the live stacking module. Always 3 of these prestacks will be added together to provide a 6 frame stream preview mini stack. Optional actions
Stream analysis infoIn the bottom right of the PEAAnuts window, a few data are printed which are generated from the cross section intensity plot. In the plot itself, markers indicate the lower and upper detection threshhold and the 'rim area', in which slope evaluation is perfomed.
The higher the slope values and the high threshold diameter, the better is the focus. For the isoline distance and the diameter at the low threshhold, it is the other way round, the smaller the value, the better the focus. The slope values and the high threshhold diameter are normalized to value of 1000. This value cannot be reached in practice, so no saturation effects can occur. It needs some time to gain experience in using the values. The help they provide accumulates in the long run, e.g. when you remember which value ranges can usually be achieved for different planets and optical equipment. This then helps in later nights to judge if further tweaking makes sense or if it is better to be satisfied with the actual setting because one knows it cannot get much better in situations like these. Note that the evlauation data depend on the current image brightness and seeing, so their use is only reliable if the circumstances remain approximately constant. For evaluation, exposure and gain can be set such that the graph reaches almost up to the maximum, but avoid overexposure. IOW, stream analysis is best performed at higher image brightnesses than the ones recommended for recording or stacking. But this is not mandatory, it also works to use the typical 70% brightness/histogram level and monitor the data during live stacking and/or stream recording, including optionally focus correction during the process. (Generally, a motor focuser is needed for that). Evidently, using the slopes works best for Mercury, Mars & Venus, and less good for Jupiter and Saturn, due to their smoothly decreasing limg brightness. Isoline display and ADC tuning infoThe isoline feature also stems from the predecessor of the PEAAnuts plugin (ImageInfo). It is not supported extensively anymore, but is still kept integrated, just in case it might be useful for someone resp. some task. Isoline steps and legend are set up automatically dependent on the actually detected max. brightness in the image.A 'special hack' is the use of the isoline display for ADC tuning. In color mode, two different isoline sets are calculated for the red and blue channel, respectively. The resulting pattern is quite self-explanatory. The lesser the overlapping of the red and blue set, the better is the ADC adjustment. ![]() |