I was about to write the same email (thank you Vade). Thank you Miroslaw, but yes - what you're doing is more of a diffusion - blending between a blurred and clean image...
I think I get it now. The degree of blur is determined by how much a pixel is averaged with its surrounding pixels. If you control that with a value from a mask image, you will have a compound blur... Patrick On Aug 13, 2010, at 1:12 PM, vade wrote: > Blending between a blurred and un-blurred image does not produce a variable > width blur. You would need n number of blurred images to do that, where n > number of images. > > What you do is blur a variable amount. : > > Note the difference in the top blur (our compound blur) > > and the mixing between a blurred and non blurred image > > http://i.imgur.com/TjCZY.png > > http://vade.info/CompoundBlur.mov > > Im sorry but I cannot disclose our algorithm, but if you research how to do a > fixed width convolution kernel blur (box or gaussian), separate it (for speed > and cleanliness) it should be apparent how an additional sampler input can > modulate a uniform float input :) > > As for the note about mip mapping, that is certainly a fast approach, and > mip-mapping is possible within QC if you use the Image Texturing Properties > patch. Note howeveer that forces GL_TEXTURE_2D (as rect is default in core > image/video and Quartz Composer), can mean some patches act very odd with an > image input thats 2D (or flat out fail if its a 3rd party QC input and they > dont check the [self.inputImage textureTarget] value when binding. Just > saying, it act odd, but really should not :) > > On Aug 13, 2010, at 2:08 PM, Miroslaw Rusin wrote: > > > >> what's the algorithm for compound blur then? >> >> attached demo with example pics from >> http://livedocs.adobe.com/en_US/AfterEffects/8.0/help.html?content=WS3878526689cb91655866c1103a9d3c597-7baa.html >> >> top-right corner picture is generated >> >> all in "Compound Blur" macro if you want to copy-paste in your composition >> >> also added blurred img cropping; you can change gaussian blur to something >> else if you like as well >> >> M >> >> <compound-2.qtz> >> >> On 13 Aug 2010, at 16:28, Stonewall Ballard wrote: >> >>> A constant blur with a modulated blend produces a different effect than a >>> true compound blur. I don't know about doing this in QC, but for other >>> work, I use a mip-map or a summed area table. Can you get at a mip-map in >>> QC? >>> >>> - Stoney >>> >>> On Aug 12, 2010, at 2:48 PM, vade wrote: >>> >>>> Thats totally not rendering correct for me, nor is it the best way of >>>> handling it. You can do it in a single custom core image filter. Im not >>>> able to hand out code, but read up on separable convolution kernels, and >>>> get it working for a constant amount for the entire image, and then >>>> modulate that amount by the intensity (a dot product) of a second sampler. >>>> Also you will need to pay attention to destination coordinates in core >>>> image, ie, ROI and DOD since you are handling multiple input images and >>>> samplerCoord may not be correct depending on your GPU, and size of input >>>> image. >>>> >>>> On Aug 12, 2010, at 2:11 PM, Miroslaw Rusin wrote: >>>> >>>>> >>>>> <compound.qtz> >>>>> >>>>> <Screen shot 2010-08-12 at 20.09.49.png> >>>>> >>>>>> >>>>>> There are often times where I want to blur an image based on a mask and >>>>>> simply using the mask to blend a blurred and a clean version of the >>>>>> image is not enough - I want to blur the image more or less, based on >>>>>> the intensity of the mask. Performance always matters, but quality is >>>>>> more important... HD in realtime is probably not doable, I'm thinking... >>>>>> so processing and rendering will be acceptable levels of performance... >>>>>> >>>>>> Patrick >>>>>> >>>>>> P.S. - I did mean Quartz Composer >>> >>> -- >>> Stonewall Ballard >>> [email protected] http://stoney.sb.org/ >>> >> >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Quartzcomposer-dev mailing list ([email protected]) >> Help/Unsubscribe/Update your Subscription: >> http://lists.apple.com/mailman/options/quartzcomposer-dev/doktorp%40mac.com >> >> This email sent to [email protected] > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Quartzcomposer-dev mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/quartzcomposer-dev/psheffield%40earthlink.net > > This email sent to [email protected] _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to [email protected]
