Archived posting to the Leica Users Group, 2004/05/10

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Subject: [Leica] RGB2GRAY plug-in
From: DouglasMSharp at netscape.net (Douglas M. Sharp)
Date: Mon May 10 11:12:45 2004
References: <006b01c436b8$711c9f00$6d01a8c0@CCA4A5EF37E11E>

Image - Mode - Grayscale which you abhor, and I'm learning to avoid to 
diminish your wrath ;-)

I've now uploaded the shot again using rgb2gray as a conversion filter , 
I'll have to play with the sliders a bit more often
to get used to it. I get the impression it's very sensitive to the 
original colour distribution.
Exactly as Tina said, it works as a one of the filter options, I hope 
thast it WILL be fun to play with when I get it all worked out.
Douglas

B. D. Colen schrieb:

>Sorry - IMG?
>
>
>
>Hi B.D.
>the problem with the I-M-G is exactly what this plug-in is supposed to 
>be correcting
>.
>I quote the readme file verbatim
>
>
>Contents of the ZIP-File
>------------------------
>
>   The files included in this archive have been developed taking into 
>account that conversions
>from RGB to grayscale with a simple mode change in Photoshop are 
>sometimes less controllable
>than necessary. Therefore, we have created a plugin (PC only) and an 
>action (a macro for
>Photoshop 4.0 and later) that enable the user to take control of the 
>weighting of the colour channels
>in the final grayscale picture. The action is available in a German and 
>an English version, because
>of the different naming conventions of layers in these two versions.
>   Both plugin and action do basically the same thing - choose the one 
>that suits your personal style
>best.
>   To install the plugin, copy it into the plugins-subfolder of the main
>
>Photoshop-folder.
>Restart the application to select the plugin from the filters-menu. Add 
>the action to your actions-
>palette with the corresponding command from the palette (click the 
>triangle in the upper right
>corner of the actions-palette to open the menu).
>
>
>RGB2GRAY.ATN
>------------
>
>   Action for PS4 (English version) to selectively convert RGB pictures 
>to grayscale.
>This action creates a picture containing four layers (the topmost being 
>an adjustment layer
>for gamma-correction).
>   Arrangement and opacity of the layers simulate the brightness of 
>colors as perceived by
>the human eye. The green layer should not be modified - changing its 
>opacity to a value lower
>than 100% will make the transparent background (checkerboard) shine 
>through, thus
>brightening the image.
>   If you want to optimize the picture using other than the default 
>values, drag the opacity sliders
>or change the gradation of the adjustment layer. If you prefer, flatten 
>the file before saving it.
>
>
>RGB2GRAY.8BF (PC only)
>----------------------
>
>   When the color sliders are set to 0, gray is composed of 30% red, 59%
>
>green and 11% blue
>(like luminance in Lab color space). Positive values on the color 
>sliders enhance the part of the
>selected color. Imagine this technique as putting a color filter in 
>front of your camera lens -
>the more intense the red filter, the darker blue sky colors appear and 
>the lighter skin tones are
>perceived. Choose a red value of 255, and 100% of the red channel will 
>be copied to green and
>blue channels.
>   The contrast slider is still in beta - it is not a full-fledged gamma
>
>corrector, but it does its job.
>Brightness works as expected. Clipping operates just like the highlight-
>
>and shadow eyedropper
>in Photoshop's levels-dialogue.
>
>   We know it's slow, has a small preview window and is constrained to 
>physical memory - but as
>it was done with Adobe's Filter factory, there is not much to be done 
>about it. We hope it makes
>your grayscale conversions a little more productive. Do not hesitate to 
>email us under the following
>addresses in case of improvements or praise ;). Please note that we 
>cannot promise to provide
>improved versions, though. The action and the plugin are freeware but 
>copyrighted by us.
>
>_________________________________________
>
>
>
>_______________________________________________
>  
>



Replies: Reply from bdcolen at earthlink.net (B. D. Colen) ([Leica] RGB2GRAY plug-in)
In reply to: Message from bdcolen at earthlink.net (B. D. Colen) ([Leica] RGB2GRAY plug-in)