I'm out of my element here, but anyway. Could you possibly scale the image up to twice the size and then do the stretching?
As a final step, scale it back down with a filter offset to keep only the odd or even pixels. Cheers, Elias Ericsson Rydberg 28 nov 2013 kl. 01:09 skrev Bryan Dunkley <[email protected]>: > > I have tried making the "stretched" part -1 and this shows that it isn't > doing every pixel as I thought. So the way i'm doing things is wrong I just > don't know how to fix it. > I'm stuck. Ive looked at the IDistort.cpp and it uses a sample instead of a > tile look up. The problem is how do I "stretch" a value using the sample so > that it doesn't leave "gaps". > > On 26 November 2013 12:00, <[email protected]> wrote: >> Send Nuke-dev mailing list submissions to >> [email protected] >> >> To subscribe or unsubscribe via the World Wide Web, visit >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev >> or, via email, send a message with subject or body 'help' to >> [email protected] >> >> You can reach the person managing the list at >> [email protected] >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of Nuke-dev digest..." >> >> >> Today's Topics: >> >> 1. Re: Re: Nuke-dev Digest, Vol 80, Issue 12 (Bo Zhou) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Tue, 26 Nov 2013 09:59:21 +0800 >> From: Bo Zhou <[email protected]> >> Subject: Re: [Nuke-dev] Re: Nuke-dev Digest, Vol 80, Issue 12 >> To: Nuke plug-in development discussion >> <[email protected]> >> Message-ID: <[email protected]> >> Content-Type: text/plain; charset="utf-8" >> >> Hi, >> >> Did you tried to generate the whole filtered image, and later output to >> scanline in order to debug your algorithm ? >> >> On 2013/11/26 9:54, Bryan Dunkley wrote: >> > Hi Ivan, >> > >> > Well spotted, this was indeed outputing only 0 and 1. I changed that >> > now that to a float to get the desired values. >> > >> > Its still very steppy tho. even with cubic interpolation...almost >> > looks like it skips a pixel between two pixel positions. >> > >> > >> > On 26 November 2013 01:49, <[email protected] >> > <mailto:[email protected]>> wrote: >> > >> > Send Nuke-dev mailing list submissions to >> > [email protected] >> > <mailto:[email protected]> >> > >> > To subscribe or unsubscribe via the World Wide Web, visit >> > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev >> > or, via email, send a message with subject or body 'help' to >> > [email protected] >> > <mailto:[email protected]> >> > >> > You can reach the person managing the list at >> > [email protected] >> > <mailto:[email protected]> >> > >> > When replying, please edit your Subject line so it is more specific >> > than "Re: Contents of Nuke-dev digest..." >> > >> > >> > Today's Topics: >> > >> > 1. pixel stretch: interpolation. (Bryan Dunkley) >> > 2. Re: pixel stretch: interpolation. (Ivan Busquets) >> > >> > >> > ---------------------------------------------------------------------- >> > >> > Message: 1 >> > Date: Tue, 26 Nov 2013 01:18:27 +0000 >> > From: Bryan Dunkley <[email protected] >> > <mailto:[email protected]>> >> > Subject: [Nuke-dev] pixel stretch: interpolation. >> > To: [email protected] >> > <mailto:[email protected]> >> > Message-ID: >> > >> > <caaygu29wuyisvatqbut1wpqhe9rvwrydk1qf2etrgo5+6cc...@mail.gmail.com >> > <mailto:caaygu29wuyisvatqbut1wpqhe9rvwrydk1qf2etrgo5%[email protected]>> >> > Content-Type: text/plain; charset="iso-8859-1" >> > >> > Skipped content of type multipart/alternative-------------- next >> > part -------------- >> > A non-text attachment was scrubbed... >> > Name: spread_artifact.jpg >> > Type: image/jpeg >> > Size: 14376 bytes >> > Desc: not available >> > Url : >> > >> > http://support.thefoundry.co.uk/cgi-bin/mailman/private/nuke-dev/attachments/20131126/9baebf05/spread_artifact-0001.jpg >> > >> > ------------------------------ >> > >> > Message: 2 >> > Date: Mon, 25 Nov 2013 17:24:13 -0800 >> > From: Ivan Busquets <[email protected] >> > <mailto:[email protected]>> >> > Subject: Re: [Nuke-dev] pixel stretch: interpolation. >> > To: Nuke plug-in development discussion >> > <[email protected] >> > <mailto:[email protected]>> >> > Message-ID: >> > >> > <CAGQmGOBQTFq=lpn4atnyb1sb+vpopjboj_dv4bqrjfmtgai...@mail.gmail.com >> > <mailto:lpn4atnyb1sb%[email protected]>> >> > Content-Type: text/plain; charset="iso-8859-1" >> > >> > Hey Bryan, >> > >> > I haven't actually checked this, but looking at this line: >> > >> > ((float*)(modifiedRow[z]))[ >> > current_value] = lerp(value,d_value,(i/stretch)); >> > >> > Wouldn't (i/stretch) always return an integer? And therefore your lerp >> > function is going to be "steppy"? >> > >> > >> > >> > >> > >> > On Mon, Nov 25, 2013 at 5:18 PM, Bryan Dunkley >> > <[email protected] <mailto:[email protected]>>wrote: >> > >> > > >> > > Hi Guys, >> > > >> > > I'm having trouble with my pixel stretch plugin, I've tried >> > linear and >> > > cubic interpolation to get from one value to another over a >> > given number of >> > > pixels. linear interpolation should get this done. >> > > I basically want a smoother blend from the start value to the >> > end value. >> > > >> > > attached is an image of the result I currently get. >> > > >> > > any help would be great thanks. Bryan >> > > >> > > for (;X<r;X++) >> > > { >> > > float shift = (multiplier*distortionValue[X]); >> > > int stretch = int(shift)*-1; >> > > >> > > foreach (z, channels) >> > > { >> > > for (int i=0; i <= stretch; i++) >> > > { >> > > if ((X-stretch) < X) //check for out of bounding box >> > > { >> > > break; >> > > } >> > > else >> > > { >> > > float value = tile[z][y][X]; >> > > float d_value = tile[z][y][X+stretch]; >> > > >> > > int current_value = (X-stretch)+i; >> > > >> > > if (stretch != 0) >> > > { >> > > //LINEAR INTERPOLATION >> > > //((float*)(modifiedRow[z]))[current_value] = >> > > lerp(value,d_value,(i/stretch)); >> > > } >> > > else >> > > { >> > > ((float*)(modifiedRow[z]))[current_value] = value; >> > > } >> > > } >> > > } >> > > } >> > > } >> > > >> > > _______________________________________________ >> > > Nuke-dev mailing list >> > > [email protected] >> > <mailto:[email protected]>, >> > http://forums.thefoundry.co.uk/ >> > > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev >> > > >> > > >> > -------------- next part -------------- >> > An HTML attachment was scrubbed... >> > URL: >> > >> > http://support.thefoundry.co.uk/cgi-bin/mailman/private/nuke-dev/attachments/20131125/044c07b9/attachment.htm >> > >> > ------------------------------ >> > >> > _______________________________________________ >> > Nuke-dev mailing list >> > [email protected] >> > <mailto:[email protected]>, >> > http://forums.thefoundry.co.uk/ >> > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev >> > >> > >> > End of Nuke-dev Digest, Vol 80, Issue 12 >> > **************************************** >> > >> > >> > >> > >> > -- >> > Bryan 'Fox' Dunkley >> > Compositor / Python, C++ Developer >> > >> > tel: +44 755 268 2117 >> > website: www.slyfoxfx.com <http://www.slyfoxfx.com> >> > linkedin: http://www.linkedin.com/pub/bryan-dunkley/26/b21/bab >> > >> > >> > _______________________________________________ >> > Nuke-dev mailing list >> > [email protected], http://forums.thefoundry.co.uk/ >> > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev >> >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: >> http://support.thefoundry.co.uk/cgi-bin/mailman/private/nuke-dev/attachments/20131126/d8f4dba4/attachment.html >> >> ------------------------------ >> >> _______________________________________________ >> Nuke-dev mailing list >> [email protected], http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev >> >> >> End of Nuke-dev Digest, Vol 80, Issue 14 >> **************************************** > > > > -- > Bryan 'Fox' Dunkley > Compositor / Python, C++ Developer > > tel: +44 755 268 2117 > website: www.slyfoxfx.com > linkedin: http://www.linkedin.com/pub/bryan-dunkley/26/b21/bab > _______________________________________________ > Nuke-dev mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-dev
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