I'm still not quite sure how to use Match Color but I just did do a
little experiment with the shell and (sort of) duplicated your results.
With some more practice I think I'll have it. And I do agree it's
much better over a large area where there *is* luminance data to work
with. As you noted, David's shot had no luminance data at all so
everything had to be constructed from scratch. I think the best
approach there was painting under mask. If you us a low opacity and
flow rate then you can create a bit of variation here and there such
that it doesn't look artificial.
Chuck Norcutt
Moose wrote:
> Chuck Norcutt wrote:
>> Whatever you might have said about color match (actually, look for "match
>> color"
>
> Oops, sorry about the word reversal.
>
>> or you won't find it in PS help) has been lost to my leaky memory since I
>> a) didn't remember such a thing existed and
>> b) haven't been able to figure out how to use it.
>>
>> Using curves is actually pretty simple and can be done in about 30 seconds.
>> <snip details>
>>
>
> That technique works fine where there there is no luminance detail at
> all and on very small areas. In this set of images of David's, that's
> mostly true. On 3, though, painting a single color onto the woman's
> chest would look very artificial, whereas Match Color retains the subtle
> luminance shading, even into the shadows, while recreating the lost skin
> tones.
>
> The details of highlight recovery vary with different RAW converters.
> According to dpreview's comparison, ACR was the most aggressive in
> recovering color detail, even where correct color is lost through
> unrecoverable clipping of 1-2 channels. Some other converters are more
> conservative, simply going completely to shades of gray in the areas
> where at least one channel has clipped. Dcraw has options for highlight
> color recovery from very conservative up to a very aggressive level of
> color inference, which varies in results from very good to useless.
>
> Where color is lost, but luminance detail remains, Match Color can do
> apparent magic. Ian's snail is a good example. Simply using the PS
> Highlight tool recovers lots of compressed luminance detail, but with
> almost no color. Whether this is a result of highlight recovery in RAW
> conversion or of JPEG processing doesn't matter here, only that it
> provides such a clear example.
>
> In the original, both color and luminance detail are lost to the eye
> over a large part of the shell. Roll over the image to see what is
> recoverable with Highlight. Almost the whole of the shell now has
> luminance detail showing the texture and patterns of the subject, but
> the bright area is almost pure grayscale. Click on the image to see what
> Match Color can do.
> <http://www.moosemystic.net/Gallery/Others/Swiss/Snail.htm>
>
> Match Color takes the color palette of a source image or selection and
> overlays it on the luminance information of a target image or selection.
> It also has a Luminance slider to move the resulting palette brighter or
> darker and other adjustments. If done on a separate level, the same
> selection used for Match Color target can be set as a mask. I usually
> choose a slightly larger than necessary target area, to allow edge
> refinement of the mask. For the snail, I chose as source most of the
> non-clipped shell and for target, the blown area. The colors are a
> perfect match because they come from the same subject in areas not
> overexposed.
>
> I can't imagine correcting the snail by hand; the labor would be much
> greater than simply copying color palette across. I don't think that
> simply manipulating Levels & Curves by channel could do it right, as the
> mix appears to change with brightness.
>
> I also know that there are variations in subtlety of color perception.
> David, AG, C.H. and others here appear to have more of that than I do.
> When I used to go birding with a friend, it was amusing when a bird flew
> by for just a glimpse. She would pick up the colors better than I and I
> would pick up the shapes, bars and marking details that she missed.
>
> Using Match Color, I don't have to rely on my color vision to get the
> replacement color right, it comes from the image itself.
>
> Moose
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|