mountainman 0 #1 April 15, 2002 Hi there folks.I saw the "you might be a frame grab if" and am curious on how you can uninterlace/interlace the picture to make it look better.I saw once that it has to do with taking out one of the channels, I think.If you could explain to me how to do it, I would like to do that with mine since they look so incredibly bad.Thanks! PS No, I'm not submitting.JumpinDuo.com...come and sign the guestbook. Quote Share this post Link to post Share on other sites
quade 3 #2 April 15, 2002 You're going to have to have access to a good pixel based image editing program. PhotoShop or PhotoShop Elements works quite nicely.The first step is to make the frame grab. Most video programs can do this, but depending on the video program you have, it might save it as 640x480 or 720x480. If you can, save it as 720x480 in whatever might be native to your operating system. On a Mac, that would be a pict file.Next import the file into your image editing program.Next you'll want to go into the PhotoShop filters and select "video > de-interlace". At this point PhotoShop asks if you want to replace the lines that get removed by duplication or interpolation. I like interpolation.At this point, you're basically done. All that's left to do is put it back into the original aspect ratio. Resize the image to 640x480.There are some other techniques that can fake up the resolution a bit, but not much.Here is a page I wrote about the basic prosess a couple of years ago.Attached is an original image I recent worked on and in the next post I'll attach my basic tweeks plus a little image enhancement.quadehttp://futurecam.com Quote Share this post Link to post Share on other sites
quade 3 #3 April 15, 2002 Attached is the cleaned up image.quadehttp://futurecam.com Quote Share this post Link to post Share on other sites
mountainman 0 #4 April 15, 2002 Hey Quade...that is exactly what I was looking for. Do you have that on your website? Seems that I've seen that before. Thanks again.JumpinDuo.com...come and sign the guestbook. Quote Share this post Link to post Share on other sites
indyz 1 #5 April 15, 2002 If you don't have Photoshop and don't want to buy/steal a copy, the Gimp has a pretty good deinterlace filter. Attached is Paul's test image with the evens removed and rescaled to 640x480, saved as a jpeg with the quality at .75 or 75%, however you want to look at it. I didn't do a side-by-side comparison, but removing the odds looked good also, at least with this image.--Brian Quote Share this post Link to post Share on other sites
AggieDave 6 #6 April 15, 2002 Quade, I'm pretty good with Photoshop, and I had already done the filter trick, as well as playing with different amounts of blur, sharpen and a few other color things. Take a look at the frame grab I attatched, see the color streaks, ideas?A human cannonball, I rise above it allUp higher then a trapieze, I can fly Quote Share this post Link to post Share on other sites
quade 3 #7 April 15, 2002 Dave --Lemme guess, you took the composite video output and fed it into an analog to digital converter (possibly a USB device) to get it into the computer? Maybe your copy of the video was a VHS dub?Yeah, unfortunately, there's just so much you can do with that. Reducing the image size like you've already done helps, but only so much and you end up with a smaller image.For the best results you want to do the computer input directly off of the miniDV through a FireWire port.quadehttp://futurecam.com Quote Share this post Link to post Share on other sites
AggieDave 6 #8 April 15, 2002 Yup, it was a composit transfer from a PC1 to a VHS then from a VHS to my computer with a composit.Oh, well, I was thinking you might know a trick I didn't.A human cannonball, I rise above it allUp higher then a trapieze, I can fly Quote Share this post Link to post Share on other sites
quade 3 #9 April 15, 2002 Not bad. Where I start to notice a slight difference is the aliasing (stair step) on the right leg in the transition between the dark area of the leg and the lighter background. Very slight difference though.After working with this type of thing for awhile, you'll begin to notice what works and what doesn't. Actually, with the proper tweeking, frame grabs aren't bad for the web and print up ok for 6x4inch images. They fall apart quite rapidly the larger they get.quadehttp://futurecam.com Quote Share this post Link to post Share on other sites
indyz 1 #10 April 15, 2002 I'm wondering if it would look much better if I ran it on an image that hadn't already been subjected to lossy compression. Do you know anywhere I could download a framegrab saved as a raw BMP or PICT?--Brian Quote Share this post Link to post Share on other sites
quade 3 #11 April 15, 2002 The original is too big for me to upload here.Send me your email address and I'll send you the original pict.quadehttp://futurecam.com Quote Share this post Link to post Share on other sites
indyz 1 #12 April 15, 2002 Thanks for the pict Quade. I think something is going on when I convert from the pict to a bitmap so the Gimp can read it. I'm actually getting worse results with the uncompressed image.--Brian Quote Share this post Link to post Share on other sites
freeflyfree 0 #13 May 6, 2002 This thread has been one of the most practical and helpful that I have come accros lately...Thanks guysBlue SkiesNO FEAR, NO LIMITS, NO MONEY..."A Subitánea et Improvísa Morte, Líbera nos, Domine." Quote Share this post Link to post Share on other sites
