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Post by Richard Russell on Feb 26, 2012 14:46:52 GMT
In a recent thread somebody kindly posted details of how to use PhotoShop to export an image in the .Y format needed by the Colour Recovery program. Finding myself in need of this information I've been searching for the thread, but I can't find it anywhere! Can somebody help me locate the thread, or failing that would the person who posted the information be so kind as to do so again?
Richard.
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Post by Alex Weidmann on Feb 26, 2012 15:07:58 GMT
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Post by Charles Daniels on Feb 26, 2012 15:11:25 GMT
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Post by Alex Weidmann on Feb 26, 2012 16:21:09 GMT
With my rather old version of Photoshop, I simply select "Grayscale" from the "Mode" drop-down menu. Then "File", "Save As", and select "Raw" from the "Save As" drop-down. (It also gives you a list of options for the raw format, such as header-size; but the default options are the correct ones required for your software.)
Not sure if they've changed this with newer versions, but should be similar.
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Post by Richard Russell on Feb 26, 2012 16:39:25 GMT
With my rather old version of Photoshop, I simply select "Grayscale" from the "Mode" drop-down menu. Then "File", "Save As", and select "Raw" from the "Save As" drop-down. Thank you. I don't have PhotoShop myself (that being the problem: I want to be able to tell somebody else how to do it, but can't try it out first) but I'll pass that on. I think the instructions given before included how to scale the image to 1920x1080 as well. Is that easy? Richard.
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Post by Charles Daniels on Feb 26, 2012 16:55:22 GMT
With my rather old version of Photoshop, I simply select "Grayscale" from the "Mode" drop-down menu. Then "File", "Save As", and select "Raw" from the "Save As" drop-down. Thank you. I don't have PhotoShop myself (that being the problem: I want to be able to tell somebody else how to do it, but can't try it out first) but I'll pass that on. I think the instructions given before included how to scale the image to 1920x1080 as well. Is that easy? Richard. Image scaling is very simple. I'm not sure what the steps are in Photoshop, as I don't have that program. But it will be pretty easy to find from the drop downs on top.
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Post by Alex Weidmann on Feb 26, 2012 17:46:00 GMT
In my version you select "Image Size" from the "Image" drop-down. Then change the default units from cm to pixels, and enter the size parameters. It also asks you to define resolution in pixels per inch; though I wouldn't be surprised if that option has been dropped in more recent versions. Would expect them to have added different resampling options too. That reminds me of something I meant to ask you actually: in my new AviSynth script I'm down-sampling an HD Y8 stream to SD. Currently using Lanczos with 12 taps; though not sure if that's optimal? (I'm working on the luma component only, filtering out the chroma at a later stage.) These are the various options: avisynth.org/mediawiki/Resampling
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Post by Simon Broad on Feb 26, 2012 18:08:53 GMT
It was me who made the thread and giles gave the info but the thread was locked for some reason. Richard Russell: Can you please tell me where i can find a telerecording of dw episodes with chroma dots on IE: Mind Of Evil Ep 2?? Or could you upload some footage??
Thanks
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Post by Richard Russell on Feb 26, 2012 18:09:27 GMT
That reminds me of something I meant to ask you actually: in my new AviSynth script I'm down-sampling an HD Y8 stream to SD. Currently using Lanczos with 12 taps; though not sure if that's optimal? (I'm working on the luma component only, filtering out the chroma at a later stage.) These are the various options: avisynth.org/mediawiki/ResamplingThat link isn't working for me, but if you want to downscale 1920x1080 to 720x576 I'd recommend using filters at least as good as those I use in the CR process itself. Here are the curves; the relevant ones are the Luminance downconversion filter (horizontal) and Luminance downconversion filter (vertical): colourrecovery.wikispaces.com/Response+curvesAs you can see they are both 31 tap optimised FIRs, with 3 phases and 8 phases respectively. My paper on downscaling is here: www.rtrussell.co.uk/filters/fdscale.htmlRichard.
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Post by Simon Broad on Feb 26, 2012 19:20:02 GMT
It was me who made the thread and giles gave the info but the thread was locked for some reason. Richard Russell: Can you please tell me where i can find a telerecording of dw episodes with chroma dots on IE: Mind Of Evil Ep 2?? Or could you upload some footage??
Thanks
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Post by Alex Weidmann on Feb 26, 2012 19:30:58 GMT
Thanks Richard. I doubt any of the AviSynth resamplers are as good as yours! These are the only ones available:
1.4.1 Nearest Neighbour resampler 1.4.2 Bilinear resampler 1.4.3 Bicubic resampler 1.4.4 Windowed sinc resamplers: 1.4.4.1 Sinc resampler 1.4.4.2 Lanczos resampler 1.4.4.3 Blackman resampler 1.4.4.4 Spline resampler (16, 36 or 64) 1.4.4.5 Gaussian resampler
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Post by John Wall on Feb 26, 2012 19:39:50 GMT
It was me who made the thread and giles gave the info but the thread was locked for some reason. Richard Russell: Can you please tell me where i can find a telerecording of dw episodes with chroma dots on IE: Mind Of Evil Ep 2?? Or could you upload some footage?? Thanks I suspect that's all protected. High resolution scans of Pertwee telerecordings aren't going to be dished out like sweeties !
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Post by Rob Moss on Feb 26, 2012 21:52:27 GMT
It was me who made the thread and giles gave the info but the thread was locked for some reason. Richard Russell: Can you please tell me where i can find a telerecording of dw episodes with chroma dots on IE: Mind Of Evil Ep 2?? Or could you upload some footage?? Thanks Simon, the thread was presumably locked because it became clogged up with your hand-coloured screen grabs from Timeslip.
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Post by Simon Broad on Feb 26, 2012 21:57:38 GMT
Oh it wasnt just me thow!!
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Post by Richard Russell on Feb 26, 2012 22:34:38 GMT
1.4.4 Windowed sinc resamplers: 1.4.4.1 Sinc resampler 1.4.4.2 Lanczos resampler 1.4.4.3 Blackman resampler 1.4.4.4 Spline resampler (16, 36 or 64) 1.4.4.5 Gaussian resampler I'm confused that the "Spline resampler" and "Gaussian resampler" are listed under "windowed sinc resamplers"; that's surely a mistake? Assuming only 1.4.4.1, 1.4.4.2 and 1.4.4.3 are the genuine windowed sinc resamplers, almost certainly one of them will be the best choice, but it's not at all obvious which! I would suggest, if you have the time, you discover their impulse responses (by the simple strategy of creating an image containing an impulse, on a mid-grey background) and then run the outputs through an FFT to obtain the frequency responses. Then you will be easily able to see which most closely approximates the ideal response you need. Richard.
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