What is Raster Decimation

[jonnystv]

Dear All

Can anyone tell me what "raster decimation" is, in relation to capturing 1080 formats with the HVX200.

Look forward to hearing from you.

Jonny

[J.R. Hudson]

Why ?

[John Froton]

A raster is the series of scan lines from the CCD that make up a picture. All of the scan lines that make up a frame of video form a raster.

Decimation is when a divided portion of the raster is stored or used.

So raster decimation in the HVX200 would be a methodology used to scale down full raster images from the CCDs for processing purposes.

Maybe Barry knows the specifics regarding the HVX200 and whether or not raster decimation is used and how it is used if applicable.

Me curious :)

[jonnystv]

John

Thanks for your clear and succinct reply. Easily understood when well illustrated.

I am very new to HD capture formats and standards, in fact pretty new to digital video in genral. So its pretty easy to start learning from the the bottom, top and middle at the same time.

The inspiration behind this question can be found here: http://www.24p.com/HD_Profiles.htm.

I don't know how old these details are but I'm attempting to scale a steep learning curve very quickly so I should probably have also asked if the HVX200's capture of 1080 HD formats is "raster decimated." And if the information in the linked table relates just to DVCPRO-HD when it is imported into Avid.

Cheers
Jonny

[John Froton]

You're welcome Jonny.

By stumbling onto this forum, you have probably come to the best place to tackle a steep learning curve on many things. There are so many great members that have a wealth of knowledge and have no qualms about passing it on.

I am also curious just what the raster decimation within DVCPRO HD means. My best guess would be something to do with how it compresses the raw signal from the raster images from the CCDs. It probably decimates (takes some kind of a percentage) of the full raster when it compresses rather than taking the whole raster.

Does anyone know for sure?

Barry?

[Christopher Barry]

I will have a guess. Raster Decimation pertains to, say, 1080 formats like HVX/DVCProHD 1080p24 being made up of 1280x1080. HDCAM being 1440x1080 and then there is HD-D5 being being 1920x1080. My guess, where there is no full pixel count of 1920x1080, it is a form of Raster Decimation.
Totally guessing, probably regret writing this. I await flaming. :violent5: