Let’s say you’d like to place a detailed bitmap image over a colorful background that you created in InDesign. The image shown here is a perfect example.
In order to achieve this effect, you must drop the white area surrounding the flower. Rather than applying an InDesign clipping path, which rarely looks natural enough to actually use in a layout, you must extract the image from its background in Photoshop. There are several ways you can go about doing this, but only one way that will give you the results you want without having to spend a lot of time in another application.
You could do it the “old school” way by drawing a clipping path around the flower in Photoshop and saving it as an EPS; however, to do so would be very tedious and time consuming, even for someone who is an expert at creating bezier paths with the Pen tool. And even though the EPS path would appear much more precise than the InDesign clipping path, the hard edges would still appear just as unnatural.
A better option, (but still not the best), would be to use the Extract filter and place a transparent PSD in InDesign. The first problem with the Extract filter is that it’s no longer native to Photoshop CS4. I know. It’s hard to believe, but if you don’t believe me, go check under the Filter menu. It’s not there! Photoshop is notorious for keeping outdated legacy features around and never removing them, but with CS4 they’ve started to. Why they’ve decided to remove something as useful as the Extract filter and keep other far less useful filters around (Blur More?) is beyond me. But according to John Nack’s blog, they’re planning to incorporate some new extract features into future versions of PS without the use of a filter. For now, the good news is that Extract is still available as an optional filter. It’s in the Goodies folder on your CS4 install disc, or you can download it here.
The other problem with the Extract filter is that working with it is just as tedious and sometimes even more time consuming than drawing a path with Pen tool. The benefit to using it is that you can get nice, natural soft edges. But to trace a detailed image like this one with the Extract filter’s Highlight tool would take forever and a day–even with the Smart Highlight feature enabled. There must be an easier way…Background Eraser? No, don’t even bother. Now there’s a legacy feature that should have been removed.
The Extract filter is definitely still the tool to use when you need to remove an image from a detailed background. But to remove an image such as this flower from a white, or solid color background and place it in InDesign, you’re better off making a selection and saving it as an alpha channel.
All you need to do is click once in the background area with the Magic Wand tool set at a very low Tolerance setting (7 in this instance). The low Tolerance setting allows you to capture more detail around the edges of the flower. Then choose Select > Similar. You now have the entire background selected, including all of those tiny white areas between the leaves of the flower. Now inverse the selection by pressing Cmd/Ctrl+Shift+I. Wasn’t that easy? In just a matter of seconds you bypassed all the extra work involved with using the Extract filter.
The next step is to make sure the selection edge is not too hard or soft. You want to make sure that your image will appear natural when you place it in InDesign. Click the Refine Edge button in the Control panel to open up the Refine Edge dialog box. In order to see the selection edges more accurately, you should preview them over black, as shown here. For a soft, detailed image like this one, I would recommend increasing the Radius value and setting Feather to zero.
The last step is to save the selection as an alpha channel. Choose Select > Save Selection. In the Save Selection dialog box that appears, enter a name for the alpha channel and click OK. Finally, save the image as a PSD, making sure that Alpha Channels is checked in the Save As dialog box.
Now return to InDesign and choose File > Place. In the Place dialog box that appears, turn on Show Import Options. Browse to the image on your system and click OK. In the Image Import Options dialog box that appears, click the Image tab. Choose the alpha channel from the Alpha Channel drop down list and click OK. Now place the image over the colored background. 
Alpha channels are always created from selections. Therefore, if you practice making accurate selections in Photoshop quickly and easily, you can store that information as an alpha channel in a PSD and make good use of it in your InDesign layouts.
This article was last modified on December 13, 2022
This article was first published on November 20, 2008
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