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Showing results for tags 'Stacking operator'.
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I am working with astro photos, converting the raw image to 16 bit TIFF images and stacking them. I have a few suggestions for you that would make my work smoother. I would be very grateful if you would implemented them. Suggestion 1: Would it be possible to change the default stack operator, like in the settings? I commonly use mean value rather than median value, and always have to correct it. Suggestion 2: Using Levels Adjustment, I have noticed that it is indeed possible to use decimal values for Black Levels, for instance 1.5 %, although this is not documented. This is very useful when working with 16 bit images. However, the value shown will always be the rounded integer value, in this case 2, even when the decimal value is used. Would it be possible to show a decimal digit, at least for levels below 10% ? Like, it would show 1.5% as the decimal value 1.5% instead of the integer value 2%. Suggestion 3: When working with astro photos it is very common to first subtract the dark current image, and then divide with a flatfield image. Subtraction is easy to do using the Subtract mode, but how to perform division is not so easy to find. By googling I have found that division is indeed possible to do by adding the flatfield image layer, adding an Invert Adjustment layer to it, and then changing to Colour Dodge mode. Since this is a "hidden" feature, would it be possible for you to simply combine these two steps into one, and name it Divide mode? A good reason for this: Any serious astro photographer who fails to find this hidden feature when searching the current documentation, and mistakenly rejects the usefulness of Affinity Photo because of this, would be pleasantly surprised to find that the feature does exist. P.S. I am currently using Affinity Photo 1.8.2 on a Mac.
Dear Affinity Staff, Thank you so much for Affinity Photo for MacOS! The 1.5 update is absolutely amazing! I hereby request the addition of another stacking operator, namely a mode (or type) value stacking operator. This operator would choose the most common value for each pixel in a stack. (I hope that I am not hereby double posting such a request) Let me give a background: I am working with projects involving trying to remove moving subjects in city shots, for example a series of shots at a very crowded crossing in Tokyo. Even with 70 shots, median still gives a poor result. I am guessing that the fact that the crossing is almost black and white means that the median values will not always be one of the background pixels, but instead someones jacket, or what not, that is more middle grey in tone. Now I think that the possibility of having photos not choose mean or median, but the mode value (most common value), of each pixel, could be handy in such situations. Suppose that for a specific pixel in my stack, only 10% of the images would actually show the background, and that, moreover, it would be at an extreme value (either black or white). Then both mean and median would fall short, but a mode value would then probably still give the correct result, and remove the ghosts, since these would all be random values. Now, I guess there are some troubles here, of course, like the fact that most probably, the ”correct” background pixel value would be slightly different in each frame. But I guess that you guys could come up with some smart way of working around this, like allowing for an interval around the mode value to be distinguished from the other (incorrect) values, and then e.g. choose the mean value of of this range of values. Or something like that. I hope to see such an operator in a future update. Thank you again for a wonderful app, that just keeps getting better in a quick pace! Best wishes from Sweden!