AS!2 Quality Graph

[jambouk]

What are the two axes on the quality graph in AS!2, and what does the length of the grey lines represent?

 

[Owmuchonomy]

Hi James, See below. I move the frame slider in the image window to monitor which are the best frames then use the best one as a reference frame. The green vertical line moves along as you move the slider. I pick the frame with the highest peak as the best. I also estimate the % frames subjectively based on the position of the green 's' curve.

"After the analysis is finished, AutoStakkert! will display a quality graph at the bottom of the information column. Two plots are superimposed on each other. The jagged up-and-down plot shows the frame quality in the order that the frames were shot - it shows the varying quality of the frames based on the seeing. The green line is a plot of the quality of the frames sorted by best quality first, then dropping off to lesser quality on the right."

[jambouk]

Chris, that's useful and a good start, but I'm still not there yet... (I'm not the brightest!)

"The jagged up-and-down plot shows the frame quality in the order that the frames were shot." would suggest the x-axis is time, but the frames have been re-ordered and can't surely be appearing in sequential order as the plots always look like this with the trend of the grey lines falling from left to right. And why are some grey lines longer than others?

I'm going to try stacking a video with just a few frames to see if each grey line is one frame or not.

James

[Owmuchonomy]

2 hours ago, jambouk said:

Chris, that's useful and a good start, but I'm still not there yet... (I'm not the brightest!)

"The jagged up-and-down plot shows the frame quality in the order that the frames were shot." would suggest the x-axis is time, but the frames have been re-ordered and can't surely be appearing in sequential order as the plots always look like this with the trend of the grey lines falling from left to right. And why are some grey lines longer than others?

I'm going to try stacking a video with just a few frames to see if each grey line is one frame or not.

James

 

My plots don't usually look like that, the plot you have posted doesn't look 'real'? Mine are random across the X axis so are obviously in order of shooting And varying constantly with seeing. I'm not near my computer but from memory there is a check box which allows you to choose if you want the display in order of shooting or by rank.

[jambouk]

Yes, I think the plot I'd posted is the analysis of a PIPP output file which I'd asked PIPP to order by quality.

 

[jambouk]

OK. I ran an AVI through AS!2 with 10 frames. It plots the quality of each frame as a point on the graph and puts a line to join the points (see right hand image which I've illustrated with red circles to show each of the ten frames). The green line is really just a re-order of the points in quality order.

What is interesting, well to me at least, is there are clear [regular] cycles in the seeing when looking at the quality graph of a raw capture file (left). I wonder if this cycle time is constant, or literally does vary continuously with local and distant seeing conditions from minute to minute.

James

 

[Bizibilder]

You can spot variability of seeing over the course of an avi by looking at the plot as you have shown.  The seeing variation seems to me to be quite variable over a session but that is purely subjective.

The green line assigns 100% to the "best" single frame and 0% to the "worst" - so you need to take that into consideration when picking the number of frames to stack from the whole curve.  Ideally you want the green line to start high on the left hand side but the seeing will often prevent that from happening.

[Freddie]

The green line will always start at the top left (the best frame is always 100%) the hope is that it will stay high.