Jeff Speck's email signature has a great-looking image of the new book he co-authored with Andrés Duany and Mike Lydon: The Smart Growth Manual. It looks so good that I felt compelled to do something similar with the Original Green. Because it's a fairly complicated process, if I don't write it down, I'll never remember it. Here's how it goes:
* Copy the front cover art file to make a new file at 300 dpi.
* Cut and paste the front cover art so it makes a new layer. Name that layer "front."
* Delete the background layer.
* If you haven't already, make a PhotoShop file of the spine art at 300 dpi.
* Use Image Size to reduce the spine art width to 2/3. So if the spine is 3/4" (225 pixels) wide, reduce it to 150 pixels wide.
* Use Image Size to reduce the width of the front cover art by the new width of the spine art (150 pixels.)
* Use Canvas Size to increase the width of the cover art by the same amount, so it's now back to the original size, making sure to add all the extra space on the left.
* Copy and paste the spine art onto the cover art file, sliding it into the 150 pixel wide empty space to the left. Name this layer "spine."
* Duplicate the "front" layer (Command-J) and rename it "front reflection."
* Duplicate the "spine" layer and rename it "spine reflection."
* If your cover is primarily dark, you're going to want to lighten the spine, as if light is coming from the left. If your cover is primarily light, you're going to want to darken the spine, like light is coming from the right. Use Hue/Saturation to either lighten or darken 27 points.
* The bottom right corner of the book is going to appear to be bent back slightly, so use the Gradient tool set Foreground to Transparent from 25 points to zero. If you're making the spine lighter, set the foreground to white; if darker, set it to black. Pull up from the corner at a 45 degree angle roughly 1/3 of the way into the book.
* Use Canvas size to make the entire height of the image a little more than double its original height. If it's a 9" tall cover, make it double height plus 4 pixels; if an 11 cover, make it double height plus 5 pixels.
* Select the "front reflection" layer, Select All, and Edit>Transform>Flip Vertical. Repeat with the "spine reflection" layer.
* Select the "spine" layer. Use the Magic Wand (tolerance: 8, Anti-Alias, Contiguous) to select anything but the spine. Select Inverse to get the spine.
* Edit>Transform>Skew and pull the lower-left corner up 30 pixels.
* Select "spine reflection" in the same manner, and Skew, pulling the upper-left corner up 30 pixels and the lower-left corner up 60 pixels.
* Select "front" in the same manner.
* Edit>Transform>Warp and pull the lower-right corner in and up an equal amount... eyeball it to get it looking right. Raise both bottom handles to get a smooth, natural-looking transition.
* Warp "front reflection" an equal amount so there's always the 4 or 5 pixel difference between the image and the reflection.
* Make only the "front" and "spine" layers visible. Select Merged. Paste to create the merged image of front and spine. Rename "cover."
* Make only the "front reflection" and "spine reflection" layers visible. Repeat the process to get the merged reflection. Rename "reflection."
* Select a narrow band at the joint between spine and front.
* For each layer "cover" and "reflection," do a Gaussian Blur set to 3 pixels. This blends spine to front slightly, like in a real book where it's not a completely sharp edge.
* Set Canvas Size to reduce height, cutting off most of the reflection. Try making the canvas height about 4/7 of what it was before.
* Select "reflection" and Add Layer Mask (Layer window icon at bottom.)
* Set Gradient tool to Foreground to Transparent from 50 points to 15, using either white or black as noted above, and pulling from the bottom of the image to the top of the reflection.
* Under Layers, Flatten Image. Immediately Save As a jpg file before you forget and save over top of the PhotoShop file.