Legacy ImageMagick Discussions Archive

magick compare -metric rmse logo128_lanczos.png logo128_spline16.png -format "\n" null: 1711.18 (0.0261109) magick compare -metric rmse logo128_lanczos.png logo128_spline36.png -format "\n" null: 562.698 (0.00858621) magick compare -metric rmse logo128_lanczos.png logo128_spline64.png -format "\n ...

IMv7 Beta is ready for testing. Use CubicSpline and define filter:lobes={2,3,4}. Thanks! It works beautifully! This might be not a good test image. I can't tell any difference between Lanczos one and Spline36 one (or 16/64). Apparently, this NASA image just tries to tell us why we need to resize a ...

Makes sense to me to use whatever notation is consistent with the current notation for lanczos for example. Correct me if I am wrong, but Anthony uses lobes for the number of lobes and support for how many lobes the filter truncates it to. That's why I think filter:lobes is more appropriate than ...

-define filter:lobes={2,3,4} should be righter if you use filter:lobes={2,3,4} for Lanczos2,3,4

fmw42 wrote: ↑2017-08-15T16:04:07-07:00 OK. That makes more sense. But for support 2=n, you should evaluate (2*n)^2 = 16 values (in one dimension?). But I got originally 202 values. Please clarify the correspondence.

In two demension. Spline2 (Spline16), Lanczos2, Bi-cubic are all 4x4. Spline3 (Spline36) and Lanczos3 are 6x6.

Lanczos 2,3,4 [lobes] = Lanczos 16,36,64 [reference samples]

fmw42 wrote: ↑2017-08-15T15:45:28-07:00But is it consistent with Anthonys -define filter:lobes=X?

Yes, if you believe me... (2n)^2.

I only asked since you said earlier "the only important thing is the NASA image"? If you do not feel it is a better test, then it is OK to skip. Do you have a reference to that image and any tests done with it with respect to this new filter? I referred it because you'll get the correct image only ...

We probably cannot change the name of the existing B-spline filter (spline), unfortunately since it would break existing code that people might have developed for it. So we will have to go with either spline16 spline36 spline64 or splinelobes, unless you can think of a better name for the latter ...

I'm so sorry for the late reply. It took me time to install Xcode and stuff for building the beta (I reinstalled Mac OS last weekend). Tried the latest beta build in the linear light space (thank you very much for adding the filters). magick logo128.png -colorspace RGB -filter Spline16 -resize 400 ...

magick is asking if you can check the values he is showing for the verbose information to see if they are correct. Wait until he fixes the spline64=splne16 values. Or look in the code and see if he has implemented the formulae properly against your code reference. Checked resize.c and it should be ...

"-filter Spline -define filter:lobes=n" might be a cleaner solution, rather than having Spline16, Spline36, and Spline64 individually...? Though, IM already has Spline filter (I guess B-Spline), so it might be little confusing... lobes: 1: Spline4 - Identical to Triangle/Bi-linear 2: Spline16 3 ...

Thanks!

Yes! (if implemented)

But I guess the current Spline filter available in IM is B-Spline, and I don't know if it makes sense to have B-Spline, Spline and Lanczos in a single software.

Whoops, the graphs aren't my work (it's not my page). The term tap was inappropriate actually. I meant lobes. Number of lobes vs number of reference samples is the same as Lanczos: (2n)^2 [n=lobes] 2-lobed Spline = Spline16: (2*2)^2=16 3-lobed Spline = Spline36: (2*3)^2=36 4-lobed Spline = Spline64 ...