Invisible Backgrounds

[Mr_P]

Richard -

thanks for the info - I've got it working now...

I created a blank document in photoshop with a transparent background.
Then used the magic mask tool to select the white areas in my graphic, then inverted the mask to select my object and copied it in to my new transparent document.
Saved it as a tiff, with the settings suggested - and it works brilliantly, with no need for transparent colour effects. - Object floats over background with no noticeable distortion

One of the issues I had was that I was using coreldraw (PC) to create the tiffs - and it doesn't save transparent backgrounds, although tiff format supports them... Basically it was merging the transparent with white... hence no transparency seen.

Got a bit of work to do converting all the relevant tiffs - will try your second method mentioned.

However, I can still use transparent white or tint colour effects for making simple text graphics on white backgrounds transparent

Thanks for the help

S

[samsc]

If you have a lot of images a mac program like graphic convertor will batch convert an entire folder - if setup correctly.

( there may be other programs that do this... )

http://versiontracker.com/dyn/moreinfo/macosx/11559

[samsc]

Then used the magic mask tool to select the white areas in my graphic, then inverted the mask to select my object and copied it in to my new transparent document.

S

when you have a complex image to separate with complex edges and ambiguous boundaries, using the extract filter is much better than using the magic mask.

[peppe]

when you have a complex image to separate with complex edges and ambiguous boundaries, using the extract filter is much better than using the magic mask.

There are several nice apps if you spend some money to give you very good result when extracting or masking you pictures.Timesavers!

Extensis Mask Pro is cool:
http://www.extensis.com/en/products/...=en_US&id=1018

[Mr_P]

Quick message to say thanks for all the info - just finished the fashion show and all went well - got all the required images invisible using a mix of all the suggestions...

Got some good results with inverse tint too - but a little bit stuttery on some playback... where invisible white or black didn't as much...

[samsc]

but a little bit stuttery on some playback...

how many layers?

what discs?

Which computer?

where you using your g4 with the delta audio card?

[Mr_P]

Using 1 x layer as animated background - cloud loop (feedback video - 006 SD_Cloud010.mov)
+ 1 x layer as tiff object with either embedded invisible background (see attached) or invtint on the white background (depending upon picture) - object then moved from L to R of screen with x,y posn
(ie a shoe flying through the clouds!)

Noticed a slow down of the background as the 'shoe' moved across the screen - normal playback resumed as soon as the shoe disappeared

Using a G5 2G mac with 2GRam - clean up-to-date hired machine - think it was a SATA drive, but might have been a fast SCSI one (wasn't my G4! - I only use it for pre-production)

Incidentally - are there any issues concerning xfade between a PAL and NTSC clips? Is it recommended to stick to one format - or doesn't it matter?

[samsc]

Using 1 x layer as animated background - cloud loop (feedback video - 006 SD_Cloud010.mov)
+ 1 x layer as tiff object with either embedded invisible background (see attached) or invtint on the white background (depending upon picture) - object then moved from L to R of screen with x,y posn
(ie a shoe flying through the clouds!)

Noticed a slow down of the background as the 'shoe' moved across the screen - normal playback resumed as soon as the shoe disappeared

this image isnt huge - there should not have been any change in graphics speed.

Using a G5 2G mac with 2GRam - clean up-to-date hired machine - think it was a SATA drive, but might have been a fast SCSI one (wasn't my G4! - I only use it for pre-production)

Disc speed wont make any difference if all you had was a still moving over an animated background.
Is that all you had?

Incidentally - are there any issues concerning xfade between a PAL and NTSC clips? Is it recommended to stick to one format - or doesn't it matter?

None issues whatsoever except they are slightly different sizes, and in the real world the pixel aspect ratio is different. NTSC and PAL might have different native gammas.
NTSC is 720x480 PAL is 720x576
as far as catalyst is concerned it doesnt matter. I dont take any notice of the frame rate.

[samsc]

Noticed a slow down of the background as the 'shoe' moved across the screen - normal playback resumed as soon as the shoe disappeared

You can use the statistic HUD to see if there any slowdowns.

The three values at the bottom summarise performance.

Movies- if your movie value approaches 100% - you are doing too much with your discs. Low values are good.
Graphics - if you are drawing too many things will approach 100%. Low values good.
Timing - accuracy of playback based on overall timing. 100% is good.