Gradient background becomes pixelated at DVinfo.net

Petri Storlopare · December 7th, 2010, 03:28 AM

Hi,

I shot an event the other day and converted all the MTS-files into Quicktime but I run into a strange problem I've never seen before.

It's a blue gradient background in a large hall, and the gradient part looks very pixelated, like a very low quality photo.
Only the blue color looks like this, all others color gradients looks just fine.
It was shot in HD, 1920 x 1080, 30p with a Canon HFM31.
On the camera screen everything looks fine but the MTS-file and the converted Quicktime file looks like as described when I watch them in the computer.

I'm working with a mac, MacBook Pro, 2,8 Ghz Intel Core 2 Duo, 4 GB 1067 MHz DDR memory, OS X 10.5.8

Any idea why this is happening?

Jeff Pulera · December 7th, 2010, 10:14 AM

It's likely a limitation of working with 8-bit color, coupled with compression. I've seen the same issue with blue skies in my HDV clips. If you play the video directly out of the camcorder to an HD display, how does it look? Just to determine if the artifacts are in the original video, or are introduced during conversion to QuickTime. Also, check in your edit software if the preview display is at the highest quality.

Jeff Pulera
Safe Harbor

Petri Storlopare · December 8th, 2010, 04:06 AM

I don't have access to an HD display right now so I can't check that. Actually, no kind of TV is available where I'm right now. It's not only the Quicktime file that looks bad, but also when I open the MTS-file in Toast. And why only the blue color?

The on-camera screen is not super good and detailed, but the artifacts should show very clearly if it looked as bad as on the computer screen, I think.

Bryan Cantwell · December 8th, 2010, 09:28 AM

What program did you use to convert the file to quicktime?

Petri Storlopare · December 15th, 2010, 02:26 AM

Sorry for this late reply. I checked in every day but I didn't refresh the page so I missed the last post.

I used Toast 9 to convert the files to quicktime, and the Toast Video Player to watch the MTS files before converting.

December 7th, 2010, 03:28 AM	#1
Petri Storlopare New Boot Join Date: Dec 2010 Location: Boden Posts: 21	Gradient background becomes pixelated Hi, I shot an event the other day and converted all the MTS-files into Quicktime but I run into a strange problem I've never seen before. It's a blue gradient background in a large hall, and the gradient part looks very pixelated, like a very low quality photo. Only the blue color looks like this, all others color gradients looks just fine. It was shot in HD, 1920 x 1080, 30p with a Canon HFM31. On the camera screen everything looks fine but the MTS-file and the converted Quicktime file looks like as described when I watch them in the computer. I'm working with a mac, MacBook Pro, 2,8 Ghz Intel Core 2 Duo, 4 GB 1067 MHz DDR memory, OS X 10.5.8 Any idea why this is happening?

December 7th, 2010, 10:14 AM	#2
Jeff Pulera Major Player Join Date: Jun 2008 Location: Milwaukee WI Posts: 691	It's likely a limitation of working with 8-bit color, coupled with compression. I've seen the same issue with blue skies in my HDV clips. If you play the video directly out of the camcorder to an HD display, how does it look? Just to determine if the artifacts are in the original video, or are introduced during conversion to QuickTime. Also, check in your edit software if the preview display is at the highest quality. Jeff Pulera Safe Harbor

December 8th, 2010, 04:06 AM	#3
Petri Storlopare New Boot Join Date: Dec 2010 Location: Boden Posts: 21	I don't have access to an HD display right now so I can't check that. Actually, no kind of TV is available where I'm right now. It's not only the Quicktime file that looks bad, but also when I open the MTS-file in Toast. And why only the blue color? The on-camera screen is not super good and detailed, but the artifacts should show very clearly if it looked as bad as on the computer screen, I think.

December 8th, 2010, 09:28 AM	#4
Bryan Cantwell Major Player Join Date: Jan 2009 Location: Terre Haute, IN Posts: 277	What program did you use to convert the file to quicktime?

December 15th, 2010, 02:26 AM	#5
Petri Storlopare New Boot Join Date: Dec 2010 Location: Boden Posts: 21	Sorry for this late reply. I checked in every day but I didn't refresh the page so I missed the last post. I used Toast 9 to convert the files to quicktime, and the Toast Video Player to watch the MTS files before converting.