(Em inglês)
By Steve Bain
The applications and features described in this tutorial require CorelDRAW Graphics Suite X3 or newer to be installed.
If you've ever found the task of fine-tuning or correcting photo problems using bitmap filters to be a frustrating, trial-and-error exercise, you may wish to take a close look at the Image Adjustment Lab in Corel PHOTO-PAINT and CorelDRAW (new since X3).
You no longer need to navigate through several bitmap filter dialogs to change the basic characteristics of an image. In just one dialog, the Image Adjustment Lab enables you to experiment and evaluate different color tonal correction settings, and instantly recall and commit to the settings you’ve tested. No more grappling through dialogs, saving experimental copies, or trying to remember the slider settings you used ten minutes ago.
In this tutorial, we’ll take a tour of the Image Adjustment Lab to see how fast and easy it is to apply automatic, custom, and advanced image corrections to a few digital camera images typical of common photographic problems.
With an image open in Corel PHOTO-PAINT, you can choose Adjust > Image Adjustment Lab to access the lab’s resources. When you first open the resizable dialog (shown below), you’ll notice that it includes a working preview area on the left, adjustment sliders on the right, and a row of convenient toolbar buttons across the top.
If you’re experienced with working in other bitmap filter dialogs in Corel PHOTO-PAINT, using the previewing features and classic toolbar buttons (shown below) in the Image Adjustment Lab will be familiar territory. Use the Rotate buttons for image rotation, and the Pan and Zoom tools to change the magnification level. Better yet, use single clicks to zoom in, right-clicks to zoom out, and/or click-drags to pan directly in the previewing area. Use the toolbar buttons to switch between Full Preview, Before and after full preview, or the new Before and after split preview modes. Below the preview area, you can use the Undo, Redo, or Reset to original buttons to change the recent adjustments you’ve applied.
For basic quick fixes, use the Auto Adjust button in combination with the Select White Point and Select Black Point eyedropper tools. Easy-to-use slider controls enable you to alter the color and tone of your image. Use the Temperature, Tint, and Saturation sliders to correct color casting and adjust color vividness. Use the Brightness and Contrast sliders to tweak lightness, darkness, and/or tonal values. Or, use the Highlights, Shadows, and/or Midtones sliders to adjust specific tonal ranges. Position your cursor over each slider to view the Hints information below the sliders (shown below).
For the ultimate in experimentation tools, click the Create Snapshot button to save your current settings. A numbered thumbnail image at the current settings is added below the preview area each time you take a new snapshot. Click directly on a thumbnail to load the preview and set the slider controls to the applied snapshot settings. Try out dozens (even hundreds) of different adjustment settings for evaluation — without the need to take notes. The illustration below shows multiple snapshots of different applied settings.
For some hands-on experience, let’s explore how easily you can perform both simple and advanced image correction with the Image Adjustment Lab. We’ll examine three typical photographic candidates in need of various types of image correction and enhancement. Start by downloading and extracting the contents of this Zip file containing three digital camera images saved in Corel PHOTO-PAINT format.
The first image requires a simple color cast adjustment. The quickest way to accomplish this is by using the Auto Adjust feature which can be applied without even opening the Image Adjustment Lab. In Corel PHOTO-PAINT, open Moon.cpt (shown below).
Notice the color cast in the image is making the normally bright white moon color appear yellowish. Choose Adjust > Auto Adjust and the image is immediately whitened. To preview the results before they are applied, choose Adjust > Image Adjustment Lab and click the Auto Adjust button. Either way, the color is corrected without the need to choose any settings at all (shown below).
Experimenting with and comparing the subtle differences between image correction filter settings is often an arduous task that requires experience and a keen eye. Unfortunately, it also usually involves creating and saving multiple copies of an image across multiple document windows and testing many settings through trial and error. The snapshot feature in the Image Adjustment Lab eliminates the need for this by making it easy to recall and evaluate different settings you’ve applied. Follow these steps to see how the Image Adjustment Lab streamlines the process:
The filter effects you can apply with the Image Adjustment Lab are selection based. This means you can make adjustments to specifically selected portions of an image and reduce the time it takes to perform advanced image-correction operations. Our next photo needs different adjustment lab settings applied to specific areas making it the perfect candidate. Follow these steps to apply different settings to selected areas in the image:
As you become familiar with the new Image Adjustment Lab, you’ll likely discover tricks you can use both within the lab and before bringing an image into the lab. Here are a few to get you started:
Before applying automated image correction with the Auto Adjust feature, make sure you apply any final cropping to your image. Automated image adjustment values are determined by the entire contents of the image. If your image includes dark, bright, or vividly colorful areas that you plan to eliminate, crop first to avoid these affecting the automatic adjustment levels.
Use the Image Adjustment Lab's Before and after split preview mode to evaluate subtle changes in filter settings. If necessary, you can drag the split position to the left or right to see more or less of the preview (shown below).
While working in the Image Adjustment Lab, click the arrow button above the snapshot thumbnail list to show or hide your current snapshots (shown below).
You can create a virtually unlimited number of snapshots. Use the navigation buttons on either side of the snapshot list to scroll through your snapshots and if necessary, delete unwanted snapshots by clicking the tiny close button in the upper-right corner of the thumbnail title bar (shown below).
With more photographers moving to digital cameras for both their hobby and professional work, the Image Adjustment Lab in Corel PHOTO-PAINT and CorelDRAW is just the ticket you need to save time when performing either automated or customized image enhancements.
Steve Bain is an award-winning illustrator and designer, and an author of nearly a dozen books, including CorelDRAW®: The Official Guide.