As I mentioned earlier I use Registax to process my webcam videos. There are quite a lot of settings and controls which at first glance can be intimidating, but it's easy to use with a little practice.
The first major step is alignment. For my reference frame I try to pick a relatively high quality frame from the first 50 or so. Then comes the selection of alignment method. So far I've dealt with 2 types of target - planetary and lunar. For planetary videos I use centre of gravity alignment and drop the luminosity threshold to around 30%. This set-up means the alignment process will work for a target with few clear features that jumps around between frames, which is the case for targets such as Mars. For lunar videos I use a single, large alignment box (usually 256) centred on the most obvious feature in the reference frame. I have tried using multi-align but find that it rarely works. Since my videos are quite short (around 4 minutes) there should be little image rotation and I doubt multi-align would significantly improve my final image.
After alignment has completed the images need to be stacked. As a rule of thumb I aim to stack around 400 images which can be varied by changing the quality settings. For a good quality video the lowest quality should be around 95% of the reference frame.
The next few steps are straightforward until the final stage of adjusting wavelets and picture settings. This is something of a process of trial and error but there are some settings that work more often than others. The main controls are the 6 picture layers, the contrast and the brightness. Starting with the easy ones, I find that turning the contrast up (around 130) and brightness down (around -25) usually helps. The layer sliders enhance the detail in different parts of the image but if over-used can create an unnatural looking image. I find that enhancing layers 4 and 5 often has the best effect, usually picking values in the 10-30 range. Since it can be hard to decide on a 'best' image, I always create a set of images using a range of settings and then compare these side by side to pick my favourite.
All in all Registax is very easy to use and can turn a video into a crisp picture in about 15 minutes.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment