View Full Version : (CS2) why looks a handmade bezier curve sharp and better then a magic-wand mask?


pure
05-22-2007, 01:39 PM
hi

i want to extract 80 images, shot in raw.
the foreground has an item (shoe/bag/kitchen tools)
the background is white. later i will set the back to black/masking out

does anybody know why i dont get a sharp and same time anti-aliased extraction of the object, using the magic wand tool? especially the curves
look like if they arent anti-aliased. i would not want to get a smooth mask, like adding gaussian blur, as this isnt really sharp only smooth :-)

if i use the bezier tool (pen tool in engl.?) and draw in 300% magnification, i get a very sharp and nice mask. (especially the curves are nice and sharp) and same time the mask isnt smooth at all, only crisp sharp.

my usage/settings:

pentool: i use the option "feathered radius: 0 and anti-aliased: ON
, later when making a selection i dont use the feathered radius as it gets smooth then (feathered 0), but still looking perfect with setting "feathered radius: 0".

with magic wand: i use the option "feathered radius: 0" but it seems that the mask isnt anti-aliased. although i checked "anti-alias" box above.
would you recommend to use ""feathered radius: 1" ?

the problem is only that it would take too much time
to extract all 80 objects manually with the pentool in 300% doing
nice curves.


any idea?

thanks

Ant
05-22-2007, 01:54 PM
Channel mask. Select, expand 1, feather 1 (or not).

pure
05-23-2007, 12:23 AM
thanks i ll try that now! you mean to make a maskselection, expand 1 and fill black with 1pixel feathered, right?

Ant
05-23-2007, 06:56 AM
thanks i ll try that now! you mean to make a maskselection, expand 1 and fill black with 1pixel feathered, right?

yes. if your files are all shot the same way, more or less (ie. studio tabletop on a white sweep) you may be able to make an action you can run on each to get you close to where you need to be. fiddle around a bit and find the channel with the most contrast, dupe it and chop from there. if you set up your action to pause and wait for user input so you can tweak each file then you'll be better off.

btw, the magic wand tool isn't a good selection method really. tis like brightness and contrast adjustment or levels

cricket1961
05-23-2007, 07:45 AM
Ant

The brightness/Contrast tool has finally been fixed in CS3. It is now a viable option to use.

Pure

If you have CS3, try the quick select tool. Magic wand isn't great, but with some minor toggles you can get a decent mask.

Chris

pure
05-25-2007, 07:58 AM
no sorry, i dont have cs3 at this studio already, only at home.
cs2 is installed there.

i tried the select colorrange tool. but it was even less detailed than the magic wand tool.

may i ask how you proceed in detail, if you say "fiddle around a bit and find the channel with the most contrast, dupe it and chop from there. "

i think you are in the channel with most contrast and then make a selection with magic wand too?

the pics are all shot with white background but have a small and grey drop shadow on the ground fading to the item.

so i wonder, actually its already set on white, i only have to do a mask for the prepress company. if i use magic wand, it usually selects light areas on the item and neglects the grey drop shadow...

in the end i realized, if an object is shot on white, to extract it in order to get a mask, i simply have to use one levelslayer and raise the contrast, it looks finished! but how to get the mask then? maybe its already there. i must figure that out, thanks