Inside Geek Canada is powered by tubemogul for more information visit tubemogul.com. Hello, everyone and thank you for tuning in the inside geek Canada. My name is Evan Theis and today is our weekly Application and Tech Feature. A common question is you see on the internet regarding video is basically interlacing verse progressive and what is the difference in basically what is it, right? So basically interlacing is an old technology and is kind of a bother that is still in use today and hope that is going to be phase out in the future. By interlacing basically dates back to one NTC and the original you know CRT TV’s came in and basically what is does is a waive display in the picture. Basically, you have the picture one time because those old TVs could not handle a whole frame of the image because a video is compose of different frames coming one after another to make it seem like f flow in motion and it could not handle the entire frame.
So what it did is actually split up the frame into half and it would take the odd numbers or the odd line and the even lines and split them up. So basically you would see one, three, five, seven on one frame and then two, four, six, eight on the next frame and what they do they blend them together and when you blend them together so quickly as motion is you cannot really tell the difference. The problem is when you are trying to work with this footage for the internet or work with the Photoshop we are doing—like what I am going to show you in Photoshop here is how a freeze frame can be quite problematic.
I will just show basically why you want to try this stick with progressive or at least the interlacing send make your footage progressive in the end because it ultimately is going to be better for you and any unused of this can be watching it. So, I am just going to on a Photoshop now where I already have image open and we are proud that it work on past that did use interlacing footage.
All right, we are in the Photoshop now and this image is actually want to did back in practicum. When I was going to school and it is just a re-cut of an Avril Lavigne video. But, it did have heavily interlacing footage so I thought it would be applicable to show you guys using this image. So as you can see right at the back there is already a couple issues that you can see just from the interlacing and this is as you look at her arm here because there was movement in this particular shot. You can see it almost looks like that you know two or three and it is blurred kind of together here. Essentially, because the two fields are blending together. They do one after another consecutively as I was describing earlier how the fields kind of to flow together so this is a combination of both them because you are doing a freeze-frame as they come together.
Obviously, it does not look like it properly should like a real still image and that is because there is two fields. If you have like a video project and it is 30 frames second as interlacing, it is ineffectively 60 fields per second, which we are seeing here. Now to further illustrate my point I have a couple layers in Photoshop here that show just the specific fields. So this is the upper field or odd field that sometimes it referred to at what I zoom in here you will see that it looks really wide it out here and you can see that if I zoom in even more. Every second field is actually gone and if I were to toggle this off and put on the lower or even field you will see that the other ones are there.
Then if I where to zoom out here, go to hundred percent and put this on together you will see that it comes together as a solid image. Now if you do have an interlacing source there is a couple of things you can do on Photoshop. So I will put on the original layer here and I will zoom a little bit. So what you are going to do, there is actually a filter, specifically design for video work in Photoshop so if you do not go up to filter and you go to video you will this through here. The one that we are going to use today is the interlacing. Now basically the interlacing is a way of removing that scan lines and kind of it does the best job that it can to make it look like a progressive you know a solid image.
Let us click that. Now there is couple options here. This is basically personal preference on how you want Photoshop to approach this task then you can get it to eliminate the other even fields or create a new field by duplication or interpolation. From what I have seen with this, it basically requires the experimentations to see what it gives the best results. So let us just go to what it has no odd fields or you move them, we will use interpolation and click okay and there you go. You can see it is a little bit better. There is still some of blurring but you do not know—you no longer see the scan lines so it did do what it supposed to remove the scan lines.
Now the interesting thing is if I go back here and choose it again and we change to the fields this time. You will notice her hand is slightly more down than it was before that is because basically it taking, you know the net that essentially the next frame over is going back and fort. Now this is just how you would do with the still. Now if you were to do this with video which is probably what your mainly using for you have the interlacing video I would still recommend the interlacing which means in just removing the fields and getting basically still progressive frames or as close that it can do as possible. This can be done using a variety of programs, I usually use compressor or even can be done inside of—a program like pornograph pro or that we premier avid.
If you have a check box when you are exporting or even importing further. This is the interlacing footage and I would basically make the footage look as progressive as possible and if you are doing any kind of video for the web but that is the YouTube, Rever any the video sharing sites any of them. You want the interlacing before you upload that because all of these sites have a lot of issue with interlacing because interlacing was not designed for a computer screen. It was designed to be viewed on the web, it was design for all CRT monitors that it could not really handle progressive.
Now for the web progressive is almost necessary because if you might see some on the videos on YouTube where there is a lot of tearing as we call it. Kind of from the interlacing and it looks—it just does not look great. I mean still viewable obviously but I would suggest that you do interlacing your footage or if you are doing a still like this. This still would look a lot better than if I just froze it in the actual application and you would see the interlacing and tearing on the particular image. This would be a lot better to see that way. So in conclusion I would say if possible get a camera or find the camera that can shoot progressive and if not once you input interlace footage make sure you the interlace it before doing too much with it.
So hopefully now you have decent idea of what difference between interlacing and progressive footages and why you want to use progressive or at least the interlace here in interlace footage for any where for the web or most the work in generally in the internet. You want to try to use the progressive source or at least make it progressive for the end product. If you have any questions regarding this or any other kind of video stuff, general tech stuff application. Hopefully you might need it you can send me an email at evan@insidegeek.ca and I could take your questions in there and hopefully get back to you as soon as possible and thanks for watching and you will see online.
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