Remove purple fringing

Hi,

I was thinking that I never had problems removing purple fringing from photo's (fortunately that's been a while:-)). So shouldn't it be possible to do it for a video (scene)?

Easiest way would be a good video filter that allows the set the range for a color channel. Any software that could do that?

Here's an example for photoshop: http://www.great-landscape-photography.com/remove-purple-fringing.html

Thanks,
Lucien

Don't most of the video editors have color correction tools?I personally use Vegas,and looking at that sample picture it would be very easy in Vegas to get that purple out and make it look more normal.

Don't most of the video editors have color correction tools?I personally use Vegas,and looking at that sample picture it would be very easy in Vegas to get that purple out and make it look more normal.

I just tried the video filter in Vegas (I still have a pro trial for 2 more weeks) using the highlights color correction. That certainly works a little bit. I wish it would give me more finer control how highlights are defined but that's certainly one way trying to reduce it.

Maybe it also has color replacement like photoshop. I'll take a 2nd look (many video filters to choose from).

Well I didn't have as much success with Vegas as I hoped. There must be a video filter that allows selective saturation per channel. I'll keep looking...

In Vegas, I found it faily simple to dramatically reduce the purple fringing using the "Color Curves" video filter changing just the blue channel curve.

In Vegas, I found it faily simple to dramatically reduce the purple fringing using the "Color Curves" video filter changing just the blue channel curve.

Unfortunately that also changes the rest of the picture unless I'm doing something wrong.

The color correction #2 seems to be the best tool but I have trouble getting the right area selected.

I'll tell you, if I find this purple fringing issue to be a real issue when I get my hands on an HF10, there's no way I'm going to color correct every clip this issue shows up in. That's not an enjoyable way to shoot in my mind and is enough to rule it out for me. I'm just hoping the issue is not as bad as it is in the prosumer series.

From the clips I've seen it's only at overexposed areas. That said there's no zebra striping anymore on the HF10 to quickly tell.

From all the clips I've seen though very few had the fringing. Either way, that's a personal decision if someone can live with it.

I will do some tests specifically for this and see how bad it is and how quickly it could occur.

Okay found a video filter in Vegas.

The color corrector #2 really does work and is almost the same as photoshop's HSL/Saturation but took me a while to figure out how it works.

The procedure is:

- use color picker to choose the color(s)
- set saturation very low
- now adjust the Hue/saturation/luminance ranges to pick the right areas. To do this turn on color mask first and see if the right areas picked.

Downside is that only the pro edition has this filter (argh). The platinum edition only has the chroma keyer which will work similar but is more work (you would duplicate the video and lower the saturation on the #2, then select the areas).

thanks for the tip ! I've you received your HF100 ?

thanks for the tip ! I've you received your HF100 ?

Yes today but it's busy at work so not sure if I can test much today:-(.

I also created a virtualdub filter that works similar so that would be a 2nd (free) workaround. Downside is that it doesn't read AVCHD so you would have to convert first to MPEG2 or AVI. Might be acceptable if only a few files require converting. At least it's fixable, I can't fix slow focus issues and loss of resolution.

Sony Vegas Pro 8.0d has 30 day trial period so I still have a week left.
I couldn't find a suitable filter in Pinnacle.

Luc, I had an idea what purple fringing was,luckily never had any issuses with it yet. The sample you put up just looked like it had an overall purple shade to it,that's why my quick "easy" comment.But I did look up some other examples of purple fringing,yeah thats a little harder.One example I loaded into my Vegas 6 ,and was able to color correct quite a bit of it out but still didn't get rid of the worst of the fringing.I've used the sony color balance the most,so I used my old crutch. I boosted the red a little,turned the green down a little and the blue down even more,I turned off the preserve luminosity,then played with the hi,mid and shadow buttons.Overall it warmed the example up and seemed to make the fringing a lot less noticable.
Good luck

Sony Vegas Pro 8.0d has 30 day trial period so I still have a week left.

8.0b - I thought for a moment 8.0d was already out :(

Could you test if 24p/30p from the Canon could be read by Vegas ?

If you shoot in "Spotlight" mode (you'll need lots of ambient light) or use Evaluative WB, it drastically reduces purple fringing. The Auto WB in the HF100/10 sucks.

-Ed

Im also looking to reduce the PF form my HF10 and was wondering, is it possible to take the #2 colour corrector plug-in from the Vegas 8d trial and use it with the Movie studio version?

Might be a stupid question but i have done it in the past with a few other programs.

I have noticed PF shows up more on my PC than no my TV so im starting to live with it now.

My first Viemo video now posted. Lots of PF but then i was filming towards a window :-). Just mucking about really.

http://www.vimeo.com/1021906 (Sam playing guitar)

Dave.

I don't think you can copy the Pro filter to platinum but not sure. Alternative might be the chroma key mask filter.

In the video above you could try cinemode to see if you like that since it will get you a better dynamic range in this scene. It will look dull but if you'd do pp anyway you could add saturation/sharpness/contrast again.

Here's an example showing the use of the secondary color filter in Vegas Pro to remove the fringing: http://vimeo.com/905817

I found the color corrector works well but surprisingly in most of my recordings I didn't have that much purple fringing. It certainly helps to choose correct exposure and correct W/B at times.

I missed the other questions earlier: yes Vegas can read all types of clips. However it doesn't do any pull-down nor does it support different deinterlace settings per clip. Tmpgenc Xpress I have to say is best at this and supports all of this (but then has limited editing capabilities).

I now found a different problem with Vegas: the downscaled video is not as sharp as tmpgenc xpress or original (see comparisons here: http://lucienk.spaces.live.com/blog/cns!A4AE3FB12A26635!867.entry)

So I tried first to render as WMVHD 1080i and then rerender it with tmpgenc xpress to 720p. That worked well but my bigger Vegas project crashes at random places when I render as 1080i. I've contacted support but probably I'll simply try a different codec which should be a good workaround.

Thanks Luc.
ill try what you suggested.

Im ok with using cinema mode and then adjusting the levels in vegas.

I think you are right about the WB as well though. I have noticed some of my shots have a red cast to them. I just wished i could tell what mode i used but so far WB isn't something ive really messed around with.
Only had my HF10 for 7 days and been working most of them.

As im sticking with Vegas media studio for now ill find a way of getting rid of the PF but a week after getting my HF10 im slowly getting used to it and i guess i might even be looking harder than i should at the edges.

We are off to a Warwick Castle tomorrow and hopefully the weather wont be too good and so contrast might be better. Hope to use the cam in earnest for the first time.

Dave.

Thanks Luc.
ill try what you suggested.

Im ok with using cinema mode and then adjusting the levels in vegas.

I think you are right about the WB as well though. I have noticed some of my shots have a red cast to them. I just wished i could tell what mode i used but so far WB isn't something ive really messed around with.
Only had my HF10 for 7 days and been working most of them.

As im sticking with Vegas media studio for now ill find a way of getting rid of the PF but a week after getting my HF10 im slowly getting used to it and i guess i might even be looking harder than i should at the edges.

We are off to a Warwick Castle tomorrow and hopefully the weather wont be too good and so contrast might be better. Hope to use the cam in earnest for the first time.

Dave.

Hi Dave,

To get rid of the magenta cast in bright and sunny conditions use the Daylight W/B. It will reduce the red channel (best to test this for yourself if you like it in these conditions since it will look more yellow but the magenta cast is typically gone).

Otherwise if you don't mind switching W/B now and then to get best results matching scene, then that's the best way to go. If it's very cloudy the auto W/B should typically do just fine but if you're not sure you can always try a few W/B programs and compare it on the LCD (I found the LCD fairly accurate).

Also to reduce blown highlights you can use either custom mode with contrast to -1 (I use that now most of the time), or try some of the neutral or cinemode settings (but most would find the latter to dull looking so best to test for yourself).

Warwick Castle sounds great:-).

Here are some W/B comparisons I did (in partially cloudy conditions):
http://byfiles.storage.live.com/y1prRv2FoHMd6Q_4LgguI94iJHQecKvqqV3TrCTCCPvcBv7cd8H8RzV8WzJ1f6JiSi9RzboY0n0t-A

A warning though about cinemode: you get more detail in shadow/highlights and the image looks very 'clean' (meaning low saturation, low contrast and how sharpness). So not for everyone.

Here's a cinemode comparison with/without PP (I wouldn't use cinemode though to first get a clean detailed image to apply a lot of PP afterwards, easier to use neutral in that case since it's not as blurry):

http://zbaouw.bay.livefilestore.com/y1p20U7JNVxq5yobI13nPj0OHovF5iTm7pe4t9h4e5vxTOfr5q3PfPhd2n1XWk7TDML3RYBSITAFPahKnx0J0PDCQ

Luc.
thanks for the tips.
today its very cloudy so i think ill be ok. Im going to try manual WB most of today. I have a Pringles lid that i can hold over the lens when it sets WB. Im hoping that will be easy to do while out and about. Its a bit fiddly though.
Im also going to try your suggestion about lower the contrast to -1 but ill not use Cinema mode today. With the light being so flat i think ill need to extra boost the normal more will give.

I hope to take some good footage but as im also taking my DSLR gear i dont think ill get much. might give the HF10 to my son to use.