Another great way to add shape is to duplicate the image you wish to correct. From the main menu, select Image » Duplicate (Figure 3-21). Accept the default name, as you will be discarding the image anyway, so the name isn't important.
Figure 3-21. Duplicate the original image
Once duplicated, change this new image to a grayscale image (Image » Mode » Grayscale), as shown in Figure 3-22.
Figure 3-22. Convert the copied image to grayscale
Next, call up your Curve adjustment tool, and make a crazy curve to bring out the most definition and shape that you can muster (Figure 3-23). Once you see something you like, apply the change. Depending on what area of the image you are trying to correct, either Select All and copy the entire grayscale image or a portion of it to the clipboard, or go back to your original four-color image and make the same selection.
Figure 3-23. Use a Curves adjustment on the grayscale image
Select one of the channels by clicking on it in the Channel palettetypically the black channel, as again, the black is great for shape as long as it doesn't dirty up the imageand paste the grayscale image you created and copied to the black channel. Make sure you make the same selection on your original image as you did on the grayscale image. If you don't make the same selection on the original image, when you go to paste the grayscale image into the original image's channel, the grayscale image will not place in the correct position. I usually make and save a selection or a path with the Pen tool of the area I wish to change prior to making a grayscale copy so that each image has the exact same path or selection available. If I now go to the curve adjustment or any other adjustment tool, there will be a ton of new information to work with in the new enhanced channel (Figure 3-24).
Figure 3-24. Copy the grayscale image
Paste the grayscale image into the original four-color black channel, as shown Figure 3-25.
Figure 3-25. Paste the grayscale image into the four-color image
You may or may not want to make a color or curve adjustment to the new black channel if you find it too heavy or full. The final result is shown in Figure 3-26.
Figure 3-26. The final result shows much greater shape to the glassware