I believe I figured out a way to mimic the Drop Black tool in PE2. I got the idea when I was involved in a discussion at dpreview.com about how to mimic the
PS shortcut ctrl+alt+~ in PE2, whose solution is the key to the puzzle.
To mimic the Drop Black tool try this technique:
CREATE A GRADIENT MASK
The following steps create a Gradient Map that’s black from levels 1-2, black fading to white from levels 3-31, and white from levels 32-255 (which is similar to masking with tone using Curves (p. 84) and making levels 1-2 black and levels 3-255 white, but a Gradient Map allows you to easily fade the mask between the black and white areas of the mask.):
1)Duplicate the image or layer from which you want to eliminate the black areas, and turn off the duplicate layer's visibility and move it out of the way on your layers palette. Then, create a Gradient Map adjustment layer for the original layer.
2)Open up the Gradient Editor by clicking in the middle of the bar under the heading “Gradient Used for Grayscale Mapping”.
3)Start with the Opacity stops on the top of the gradient bar: click on each one and next to “Opacity:” enter 100% for both.
4)Now move to the Color stops on the bottom of the gradient bar. Make the left hand color stop(location 0%) black by double clicking on it and opening up the Color Picker.
5)You need to set two additional Color stops: one black and one white. Their locations need to be at levels 2 and levels 31 respectively(from the description of the Drop Black tool), however next to “Location:” you have to enter a number measured in % brightness, so you have to convert levels 2 and 31 to their percent brightness. 2/255 is roughly 1% and 31/255 is roughly 12%, so those are going to be the locations of the stops.
6)Click below the gradient bar to add a stop and enter 1% next to “Location:”, and double click on the color swatch next to “Color:” to open up the color picker to enter black as the color.
7)Click below the gradient bar and to the right of the first stop you added to add another color stop. Enter 12% next to “Location:”, and double click on the color stop to set its color to white.
8)Finally, change the color of the right hand color stop to white. What you should end up with is a gradient that is solid black from location 0% to location 1%, black fading into white from location 1% to 12%, and solid white from location 12% to 100%.
9)Close the Gradient Editor and the adjustment layer by clicking on OK, OK. You should be see a grayscale image.
10)Merge the Gradient Map adjustment layer into the original layer to form the grayscale layer.
CONVERT MASK TO A TRANSPARENCY SELECTION
11)Click on Select/All and Edit/Copy to copy the grayscale layer.
11)Create a Levels adjustment layer, don’t group it with anything, and don’t make any changes, just click OK.
12)alt+click on the mask thumbnail(the one on the right) in the Levels adjustment layer to turn off the visibility of all the other layers and enter mask edit mode.
13)Click on Edit/Paste to paste the grayscale layer into the layer mask.
14)ctrl+ click on the mask thumbnail in the Levels layer. That loads the transparency of the mask as a selection. The selection selects the whites and fades the selection into the grays and blacks (this is what ctrl+alt+~ does in full versions of Photoshop). Select/Inverse to select the blacks and fade the selection into the grays and whites.
REMOVE BLACK
15)Activate the duplicate layer you created at the beginning. Notice, the selection with the marching ants will still be active when you switch to that layer.
16)Hit the delete key to delete the blacks with a border that fades into the grays up to level 31.
You should be left with the same thing the Drop Black tool produces. It doesn't come out exactly indentical, but it is very, very close, and I attribute the differences to the rounding errors caused by converting levels to brightness percentages in the gradient map. This technique is more flexible than the Drop Black tool because you can decide how much to fade the selection. This technique is similar to what you can do with what's called "Blend If" in full versions of Photoshop.
The Hidden Power tool Clear Grayscale is even easier to duplicate. Take a grayscale image, and as in steps 11-14 above, copy and paste the grayscale image into the layer mask in a Levels adjustment layer. Then, make the transparency selection by ctrl+clicking on the mask thumbnail. However, since the selection selects the whites and fades the selection into the grays and blacks, there is no need to invert the selection in this case--all you have to do is activate your grayscale image and hit the delete key. That will produce the identical result as the Clear Grayscale tool.