https://bugs.kde.org/show_bug.cgi?id=508104
--- Comment #6 from [email protected] --- Thank you Maik for quick implementation! Tomorrow, I will provide set of photos (raw + jpeg + heic) covering many combination of focus settings (AF-C, AF-S, M VS Point, Zone, Full, Face, Subject). However, I will drop some combinations, if they all likely produce same focus metadata as AF-S single point (returning single pixel coordinate for focus area) To make it easier to test if we draw the focus frame in right place, I am planning to focus a distinct object with the same size as the focus point on the camera. About your request for understanding how large the frame around focus point is displayed, I will send you screenshots from camera. However, I did a small research for you to figure out what is best relative width x height for the frame around focus point. TLDR: If you take length of short side of the image and divide by 9, this will be equal to width=height of the square focus frame we need to draw around focus point (center of square is focus coordinates in the metadata). Basics: - Other than my own camera, I checked relevant specs and manuals of 50 fujifilm cameras released since 2010. - Each focus point is displayed as a square frame around focus point, not rectangle. - These squares makes a grid that covers photos almost entirely (with some exceptions that I will explain but they don't effect our calculations). - So, for example, if we take height of the image, and divide by how many squares are there vertically on the grid, we can find size of of each square relatively to height of the image! Aspect ratio -> width x height of grid of squares: 3:2 -> 13 square x 9 square 16:9 -> 13 square x 7 square 1:1 -> 9 square x 9 square 4:3 -> 11 square x 9 square 5:4 -> 11 square x 9 square Conclusion: - As you can see, ratio of grid dimension and aspect ratio of image almost matches. So squares almost covers the image. - Then for simplification, we can assume squares covers the image entirely. Then dividing size of the image by number of squares, we can find size of a square. - The for simplification of this, we can assume short side of the image is always equal to 9 squares (it's true with the exception of 13x7 but the smaller 1/9 is still ok there anyway) - So then size of square should be best estimated as following: width or height of square = min(image width, image height)/9 If you think this makes sense, let's take this as starting point and improve as we go through tests. Exceptions: - There is a setting to choose finer grids with half the size squares. For example 3:2 aspect ratio has 25x17 grid option in settings. However, then square focus frame we draw will be very small and not very meaningful to check focus areas by eye. - For first generation older cameras, grid doesn't cover image fully sometimes. However, it doesn't matter because square size is still same! For, example, they use 13x7 grid instead of 13x9 grid for 3:2 aspect ratio BUT each square is still approximately sized as 1/9 of shortest side of image. - I am sure there are other exceptions but this is how much I figured out by my research. -- You are receiving this mail because: You are watching all bug changes.
