IanSG Posted September 10, 2019 Share Posted September 10, 2019 Both frequency separation and high pass filtering involve separating the high and low frequency data in an image, but what are they measuring the frequency of? I understand that low frequency equates to things like tonality, while high frequency catches the detail, but I don't know what those nice sine waves that are supposed to explain things are actually showing - it's spatial separation along one axis, but what's the other? Quote AP, AD & APub user, running Win10 Link to comment Share on other sites More sharing options...
John Rostron Posted September 10, 2019 Share Posted September 10, 2019 Do not confuse the graph of sine wave frequency (=1/wavelenth) on the horizontal, against frequency (=abundance) of that frequency/wavelength) on the vertical scale, with the two-dimensional representation of the image detail expressed as the sum of sine waves of different frequencies. What frequency separation does is to separate those parts of the two-dimensional image that can be represented by a the high frequencies (of both x and y) from those represented by the lower frequencies in each of the x and y axes. John IanSG 1 Quote Windows 10, Affinity Photo 1.10.5 Designer 1.10.5 and Publisher 1.10.5 (mainly Photo), now ex-Adobe CC CPU: AMD A6-3670. RAM: 16 GB DDR3 @ 666MHz, Graphics: 2047MB NVIDIA GeForce GT 630 Link to comment Share on other sites More sharing options...
IanSG Posted September 11, 2019 Author Share Posted September 11, 2019 Hi John Thanks for that! I was too focused on the idea that frequency = Hz, and I'd forgotten that the "abundance" is affected by the radius slider, so that didn't make sense either! Quote AP, AD & APub user, running Win10 Link to comment Share on other sites More sharing options...
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