Paint Shop Pro Channels and Masks
This technique involves splitting the image into its red, green, and blue channels, then editing and combining those channels to create a mask which preserves the soft, billowing edges of the jets' vapor trails. While this technique takes a bit longer than the tool methods used in Photoshop and Photo-Paint, I think the final result is actually a bit better.
First go to Colors > Channel Splitting > Split to RGB
Below you can see small thumbnails of the individual red, blue, and green channels that are generated as new images with this command.
Examine the three new images and choose the one with the most contrast between the jets and the background and between the vapor trails and the background. In this case the red channel is the best choice for both the jets and the vapor trails. We can discard the blue and green channels and duplicate the red channel (Window > Duplicate). We'll use one copy to create a mask for the jets, and another copy to mask the vapor trail
In one copy of the Red channel, go to Colors > Adjust > Highlight/Midtone/Shadow. Adjust the sliders using "linear adjustment method" until the jets become completely black and the vapor trails disappear. My settings are shown here:
Go to Colors > Negative Image to invert the image. Then go to Image > Blur > Gaussian Blur and set the radius around 0.65. This smooths the edges of the mask a bit. The jets portion of the mask is complete.
Now go to the other copy of the red channel. Again, go to Colors > Adjust > Highlight/Midtone/Shadow. This time you want to adjust the sliders until everything but the vapor trails becomes as close to black as you can get it without loosing the soft, smoky edges of the vapor trail. You want to see some shades of gray in the vapor trail. My settings are shown here:
Most likely, there will still be some gray areas in portions of the background. We need to make this gray area totally black without loosing the gray in the vapor trails. Make a loose selection with the lasso around the area that is not totally black. Don't select the area of the large vapor trails because we want to keep the shades of gray in that area. My selection is shown here:
Go to Colors > Adjust Brightness/Contrast. Increase the contrast just enough so that the gray areas turn black. A setting of 15 worked for me. You don't want to increase it so much that you get hard edges around the vapor trails.
Now remove the selection. The vapor trails portion of the mask is complete.
Now we have two grayscale images that we need to combine to create a complete mask for our original image.
Activate the image of the white jets in a black background. Go to Selections > Select All, then Edit > Copy.
Activate the image where the vapor trails are white on a black background. Chose Edit > Paste as New Layer. If you haven't renamed any of the layers, the layer palette will show the background on the bottom, and Layer1 above it. Change the blend mode for Layer1 to Lighten via the mode menu on the layers palette.
Now your image will display the jets and the vapor trail. This image will become the mask for our original color image. You may want to merge the layers and save it at this time. You can discard the other grayscale image.
Now let's go to the original color image. In the layers palette, double click on the background and name the layer "Jets". Click the new layer button and name the new layer. This will be our new background. For this demonstration, I'm filling the new layer with a gradient fill. Choose the paint bucket, select a fill from the tool options, and click in the image to fill the layer. In the layer palette, drag this layer below the Jets.
|Select the Jets layer in the layer palette. Go to Masks > New > From Image. In the source drop-down menu, choose the grayscale image we created, and check the radio button for "source luminance".|
Click OK and the original background disappears, allowing the layer below to show through! Here's the final image...
This may seem like a lot of steps, but with practice I think you'll find this technique is useful for many different masking challenges. This image just happened to work out so that the red channel was the easiest to work with, but in some cases you may be able to use other channels to isolate various aspects of an image. I'm sure I could not have gotten such good results isoloating the soft, billowing vapor trails in this image using only the selection tools in Paint Shop Pro.
The next example is very similar to this technique, but a great deal simpler.
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Some images from Nova Development's Art Explosion 600,000.