Correcting digital photographs
Photoshop contains a number of features that let you easily improve the quality of digital photographs. These include the ability to automatically bring out details in shadow and highlight areas of an image, easily remove red eye, reduce unwanted noise in an image, and sharpen an image. To explore these capabilities, you will edit a different digital image now: a portrait of a mother and a child.Making shadow /highlight adjustments
The Shadow/Highlight command is suitable for correcting 8- or 16-bit RGB, CMYK, or Lab photos whose subjects are silhouetted against strong backlighting or are washed out from being too close to the camera flash. The adjustment is also useful for brightening areas of shadow in an otherwise well-lit image.
| 1. | Click the Go to Bridge button ( ). In Bridge, click the Lessons folder favorite(if it is not already selected), and then double-click the Lesson08 folder. Locate the 08B_Start.psd image, and double-click to open it in Photoshop. | | 2. | Choose Image > Adjustments > Shadow/Highlight. Photoshop automatically applies default settings to the image, lightening the background, but you will customize them next to bring out more detail in both the shadows and the highlights, and enhance the red sunset in the sky. (Make sure the Preview box in the Shadow/Highlight dialog box is checked so that you can see the effect in the image window.) | | 3. | In the Shadow/Highlight dialog box, check the Show More Options box, and do the following:In the Shadows area, set Amount to 80% and Tonal Width to 65%. Leave Radius at 30 pixels.In the Highlights area, set Amount to 5%. Leave Tonal Width at 50% and Radius at 30 pixels.In the Adjustments area, drag the Color Correction slider to +45.
 | | 4. | Click OK to accept your changes. | | 5. | Choose File > Save to save your work so far. |
Correcting red eye
Red eye occurs when the retinas of a subject's eyes are reflected by the camera flash. It commonly occurs in photographs of a subject in a darkened room, because the subject's irises are wide open. Red eye is easy to fix in Photoshop. Next, you will remove the red eye from the boy's eyes in the portrait.
| 1. | Using the Zoom tool, drag a marquee around the boy's eyes to zoom into them.  | | 2. | Select the Red Eye tool ( ), hidden under the Spot Healing Brush tool. | | 3. | On the tool options bar, leave Pupil Size set to 50%, but change Darken Amount to 10%. Darken specifies how dark the pupil should be. Because this child's eyes are blue, we want the Darken Amount setting to be lighter than the default. | | 4. | Click on the red area in the boy's left eye, then click the red area in his right eye. The red retinal reflection disappears. | | 5. | Zoom back out to 100% by pressing Alt (Windows) or Option (Mac OS) and clicking on the image window with the Zoom tool. | | 6. | Choose File > Save to save your work so far. |
Reducing noise
The next correction to make on this image is to reduce the amount of noise that it contains. Image noise is random, extraneous pixels that aren't part of the image detail. Noise can result from using a high ISO setting on a digital camera, from underexposure, or from shooting in darkness with a long shutter speed. Scanned images may contain noise that results from the scanning sensor, or from a grain pattern from the scanned film.There are two types of image noise: luminance noise, which is grayscale data that makes an image look grainy or patchy, and color noise, which is usually visible as colored artifacts in the image. Photoshop's Reduce Noise filter can address both types of noise in individual color channels while preserving edge detail, as well as correct JPEG compression artifacts.You will start by zooming in to the sky to get a good look at the noise in this image.
| 1. | Using the Zoom tool, click in the center of the sky above the woman's head and zoom in to about 300%. The noise in this image appears as speckled and rough with uneven graininess in the sky. Using the Reduce Noise filter, we can soften and smooth out this area and give the sky more depth. | | 2. | Choose Filter > Noise > Reduce Noise. | | 3. | In the Reduce Noise dialog box, do the following:Decrease Strength to 5. (The Strength option controls the amount of luminance noise.)Increase Preserve Details to 70%.Leave the Reduce Color Noise slider at 45%.Increase Sharpen Details to 35%.
You don't need to check the Remove JPEG Artifact box, because this image is not a JPEG and has no JPEG artifacts.NoteTo correct noise in individual channels of the image, you can click the Advanced button and adjust these same settings in each channel.[View full size image] | | 4. | To clearly see the results of your changes, click the plus button at the bottom of the dialog box to zoom in to about 300%, and then drag to position the sky in the preview area. Click and hold the mouse button down in the preview area to see the "before" image, and release the mouse button to see the corrected result. Or, make sure the Preview box is checked and watch the results in the main image window. | | 5. | Click OK to apply your changes and to close the Reduce Noise dialog box, and then double-click the Zoom tool to return the image to 100%. | | 6. | Choose File > Save to save your work so far. |
Sharpening edges
Reducing noise can soften an image, so, as a final correction to this photograph, you will sharpen it to improve its clarity.Photoshop has several Sharpen filters, including Sharpen, Unsharp Mask, Sharpen Edges, and Smart Sharpen. All of them focus blurry images by increasing the contrast of adjacent pixels, but some are better than others, depending on, among other things, whether all or part of an image needs to be sharpened. Smart Sharpen sharpens an image while also reducing noise and lets you specify whether the filter is applied to the overall image, to its shadows, or to its highlights. | For more on the other Sharpen filters, see Photoshop Help. |
| 1. | Choose Filter > Sharpen > Smart Sharpen. | | 2. | In the Smart Sharpen dialog box, do the following:Reduce the Amount to 40%.Set the Radius to 5 pixels.Choose Remove > Lens Blur.Select the More Accurate check box.
[View full size image] The Remove option determines the algorithm used to sharpen the image. The Unsharp Mask filter uses Gaussian Blur. Lens Blur detects the edges and detail in an image and provides finer detail sharpening and results in fewer sharpening "halos."Choosing More Accurate yields more accurate sharpening, but takes longer to process. | | 3. | To examine the results of Smart Sharpen, click and hold the mouse button in the preview area, then release. Or, toggle the Preview check box and watch the results in the main image window. | | 4. | Click OK to apply your changes and close the Smart Sharpen dialog box. | | 5. | Choose File > Save As. In the Save As dialog box, name the file portrait_final.psd, navigate to the Lesson08/Portfolio folder, and save the file. Then, close the image window.Congratulations. You have made several typical corrections to a digital photograph. Next, you will try something a little more unusualediting an image while preserving its perspective. |
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