HD Noob: Confused about Deinterlacing

[Adrian Gomez]

Hi, If I have interlaced footage, say 1080i, and render it as progressive 1080p, does it looses quality? I mean, is it a factor for quality or resolution loss? I have been doing the test for DV widescreen 480i to 480p and I can’t say for sure but I have the idea that I get less resolution than doing 480i to 480i.

My cam gives me interlaced upper field, if I get a lower field render does it have a problem or quality loss?

Thanks, First post of many I hope, I had a free day and have been a very productive day learning from all your posts

[John Rofrano]

Hi, If I have interlaced footage, say 1080i, and render it as progressive 1080p, does it looses quality?

Yes, you will loose some quality. If you select Blend Fields it will use both fields but the image will get a little softer from the blend. If you select Interpolate Fields, then half the vertical resolution will be thrown away because one set of fields will just be doubled. Either way, you loose quality.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Adrian Gomez]

exactly what i wanted to know about that, it’s what i like about here, and about changing the field order, does it also affects resolution? thanks thanks thanks

[John Rofrano]

and about changing the field order, does it also affects resolution?

Yes it does because you can’t change which field was recorded first. If you want to switch the field order, you have to deinterlace and then re-interlace in the opposite order. So switching the field order also causes quality loss.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Adrian Gomez]

=(
basically it means If I have a project mixed with upper field, down field and progresive, I have to choose which one retains the most quality

[John Rofrano]

Yup. You can’t have it all three ways. Usually you don’t have a choice because you delivery format will dictate which to use.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[John Rofrano]

BTW, when you asked does changing field order affect “resolution” I was reading that as “quality” so I actually answered the wrong question.

Changing field order will not change the vertical lines of resolution. You will still have all of the fields but they will be interpolated which is why I said the image would get “soft”. So it will affect “quality” not “resolution”.

Sorry if I confused things.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Adrian Gomez]

ha! also my bad for using both terms for the same thing, although I think I got what you mean, either way it seems messing with the field order or deinterlacing the output from the input footage means resolution loss.

[John Rofrano]

either way it seems messing with the field order or deinterlacing the output from the input footage means resolution loss.

I think you mean “quality” loss but yes, either way their will be quality loss.

~jr

http://www.johnrofrano.com
http://www.vasst.com