Image Editing Tips

Brighter Colors Without Distortion

You can intensify the colors of a dull photograph quite easily in Photoshop. What you may not know is that pumping the saturation (using the Hue/ Saturation dialog box) isn't the solution. When used indiscriminately, the Hue/Saturation controls can actually distort neutral tones.

Instead, use Photoshop's layers and blending modes to intensify colors while preserving the relative tonal values of a photo. Open the image file and make a duplicate layer of the background. In the Layer palette, change the blend mode for the new layer from Normal to Overlay.  It's that simple.  Try also changing the blending mode to Soft Light. (If you are looking for extreme sharpening, use Hard Light instead.)

Layer > Duplicate Layer... > OK > Overlay - (note increase in contrast) or try > Soft Light

You can control the strength of the effect two ways: You can reduce the effect by increasing the transparency of the Overlay layer (using the opacity slider in the Layers palette). Or you can intensify the effect by adding more copies of the Overlay layer. But be warned: This method increases the contrast—making dark colors darker and light colors lighter—so use it with discretion.

Accurate, Easy Selections

Selecting a portion of a digital photograph—isolating a foreground figure from the background, for example—is a completely mundane task. But if you have to draw the selection area manually, you'll discover it's a task that can waste a lot of time. This is especially true when the object has an intricate boundary (think of the leaves, limbs, and twigs of a tree against a cloudy sky). Photoshop's Magic Wand and Magnetic Lasso tools are helpful alternatives, unless there isn't sufficient contrast between the foreground and background.

You can dramatically increase the efficiency of the Magic Wand or the Magnetic Lasso by temporarily increasing the contrast between foreground objects and the background. For example, in most instances, you'll find that the foreground and background are clearly differentiated in one particular color channel—either the red, green, or blue channel in an RGB image or the cyan, magenta, yellow, or black channel in a CMYK image. Simply view the individual channel (by clicking on its name in the Channels palette), make your selection using the Magic Wand or Magnetic Lasso tool, and then return to the composite (RGB or CMYK) view to continue your work.

If you can't find a channel that contains enough contrast between foreground and background, you can use a Levels or Curves adjustment layer to force the issue. Adjustment layers are nondestructive (meaning they won't affect the original image), so you can push the contrast to the limit and even distort the image to make an easy selection. After you've made your selection (and saved it to an alpha or new channel so it's stored with the file), delete the adjustment layer to return your image to the original state.

Smoother Digital-Camera Images

Digital-camera images often contain unwanted noise—stray, randomly colored pixels that shouldn't be part of the image. Luckily, most of the noise is segregated in the blue channel. You can easily eliminate noise by selecting the blue channel in the Channels palette and running the Gaussian Blur filter.

Start with small values of less than 1 pixel; the filter softens the image. But as long as you blur the blue channel only enough to remove most of the noise, you won't notice it when you return to the full-color (RGB) image. Eliminating noise will also ensure that other operations, such as sharpening, won't introduce or exaggerate artifacts.

Great Gray-Scale Images

You can add a Channel Mixer adjustment layer (from the Layer > New Adjustment Layer menu) to your RGB image. The Channel Mixer is typically used for color adjustments. But if you click on the Monochrome option in the dialog box, the result will be gray-scale. Then use the Source Channels slider bars to determine how much data each color channel will contribute to the final image. Click on OK when you are satisfied with the results.

You can maintain the image as a layered RGB file, so you can return to the Channel Mixer layer to make further adjustments. You can also use the Image > Mode command to convert the image to gray-scale when you're ready. Photoshop will automatically apply the adjustment layer and combine the layers into one file.