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Is there any way to calculate the net/cumulative blur if an object was first blurred with value A, and then with B?
And secondly, are these blur values (Object -> Fill and Stroke -> Blur) expressed in pixels or as a percentage?
Regards,
emjotenel
PS. I'm using Inkscape v0.48 (r9654).
Gaussian blur
Re: Gaussian blur
I don't clearly understand what you mean. Using the Fill and Stroke dialog, if you blur an object with value A, then blur it some more, by value B, then whatever is showing there in the dialog is the total. Unless you mean you've blurred it, saved and imported into another image, then blur it again?
I don't think the blur units are any specific measure (pixels, inches, etc.). But I don't think they are strictly a percentage either. To me, it's complicated and I don't understand it. I do know that the size of an object affects the amount of blur that you see on the screen -- so that a blur of 1.0 on a small object might not be even be noticable, while the same blur on a very large object will be very noticable. On very large objects, I often even have to assign blur in the tenths (between 0.0 and 0.9) of whatever the units are.
Why do you need to know this info? Perhaps there is a different way to achieve what you want?
I don't think the blur units are any specific measure (pixels, inches, etc.). But I don't think they are strictly a percentage either. To me, it's complicated and I don't understand it. I do know that the size of an object affects the amount of blur that you see on the screen -- so that a blur of 1.0 on a small object might not be even be noticable, while the same blur on a very large object will be very noticable. On very large objects, I often even have to assign blur in the tenths (between 0.0 and 0.9) of whatever the units are.
Why do you need to know this info? Perhaps there is a different way to achieve what you want?
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Re: Gaussian blur
Thank you for your reply.
I actually meant what you said---blurring, saving, importing and blurring again---apologies for being imprecise. However, I have since found another peculiar trait: if you have object A blurred with value A_b, and object B blurred with B_b, then select&group them together into object C (at this point blur scale returns to zero) and blur the group with C_b, is there any way to deduct the total amount of blurring applied to either of the objects? In other words, what value A_b and B_b would need to have for them to look exactly like in the case above, but without resorting to grouping and blurring with C_b?
When looking for more info on implementation of Gaussian blur in Inkscape I found this:
http://wiki.inkscape.org/wiki/index.php/Filter_Effects
which then led me to this:
http://www.w3.org/TR/SVG11/filters.html
I actually meant what you said---blurring, saving, importing and blurring again---apologies for being imprecise. However, I have since found another peculiar trait: if you have object A blurred with value A_b, and object B blurred with B_b, then select&group them together into object C (at this point blur scale returns to zero) and blur the group with C_b, is there any way to deduct the total amount of blurring applied to either of the objects? In other words, what value A_b and B_b would need to have for them to look exactly like in the case above, but without resorting to grouping and blurring with C_b?
When looking for more info on implementation of Gaussian blur in Inkscape I found this:
http://wiki.inkscape.org/wiki/index.php/Filter_Effects
which then led me to this:
http://www.w3.org/TR/SVG11/filters.html