Page #95 (70. About Making Selections)


71. Make Areas of an Image Easier to Select

Before You Begin

70 About Making Selections


See Also

75 Select an Object by Tracing Its Edge

76 Select Areas of Similar Color


Sometimes it is difficult to see the edges of the area you want to select in an image. For example, if the lighting was not good when you took the photo, the subject might blend into the background. Or you just might have an image where there is no contrast between the objects and the background. Without enough contrast between your subject and the background, you'll find it difficult to use the Magnetic Lasso to trace its edge. If you're trying to select an area based on color, and that area doesn't contrast well enough with the surroundings, that can make using the Magic Wand tool difficult if not impossible to use. If this is the case, you can use different filter adjustments to change the area you want to select and make the selection easier.

Four specific filter adjustments work well for making an image easier to select. You can try each to find the one that works well with your particular image. You are looking for one that makes the part of the image you want to select easier to identify. For example, you can apply the Threshold adjustment to convert the image to black and white. With the Threshold effect, the light areas of the image are converted to white and the dark areas are converted to black; there are no grays. You can specify the Threshold level for the image. Everything darker than the specified threshold is converted to black, and pixels lighter than that value are converted to white. When you're looking at the image in black and white, the subject or object you want to select should be much easier to identify.

Another adjustment you can make is to group the levels of brightness in the image using the Posterize adjustment. When you select this option, you specify the number of tones or brightness levels you want, and the brightness of pixels in the image are changed so that each pixel belongs to one of the specific groups you specified. If you want to make the selection look like a photo negative, you can select the Invert adjustment. Finally, if you want to convert the selection to grayscale, you can select the Gradient Map adjustment. With any of these filters applied to the image, the area you want to select should be easier to grab using the appropriate selection tool.

If you want to use one of the available filter adjustments to make a portion of the image easier to select, first copy the image to another layer and then apply the desired filter to the copy of the layer. After you make your selection on the original layer, you can remove the duplicate, filtered layer. See 91 About Layers and the Layers Palette for more information on working with layers in PhotoShop Elements.

1.

Duplicate the Layer

Open an image in the Editor in Standard Edit mode and save it in Photoshop (*.psd) format. In the Layers palette, select the layer that contains the data you want to select. If you're working with a single-layer image, this layer is called, by default, the Background layer.

Select Layer, Duplicate Layer from the menu. A new layer is added to the Layers palette. If you're working with a single-layer image, the original layer is called Background; the copy of that layer is given the name Background copy. Although you can rename this layer, you're using it in this task only temporarily, so renaming it isn't worth the effort. See 92 Create a New Image Layer for more information on duplicating layers of an image.

2.

Apply Adjustment Filter

TIP

If you don't like the results of an adjustment filter after applying it, select Edit, Undo to revert to the previous settings for the image.

Apply the adjustment that helps isolate the area you want to select: Select Filter, Adjustments from the menu, and then choose Threshold, Gradient Map, Invert, or Posterize.

3.

Adjust Settings

When you select an adjustment filter, a dialog box opens in which you can specify the settings for the filter. For example, with the Threshold adjustment filter, you can specify the threshold level. Everything lighter than that level remains white, and anything darker becomes black.

TIP

If you select the Invert filter, a dialog box does not appear. The colors within the layer are inverted to create the appearance of a photo negative.

If you selected the Gradient Map filter, on the Gradient Map dialog box, select the gradient pattern you want to use. The filter maps the color range of the image to the range of colors within the selected gradient.

If you selected the Posterize filter, on the Posterize dialog box, select number of levels of brightness you want. If you specify 4, for example, the brightness of each pixel is adjusted to match one of those four levels. You can specify a value between 2 and 255. See 182 Make a Photograph Look Like Andy Warhol Painted It for more information on the Posterize filter.

TIP

With some images, even these filters will not make selecting a certain object with a few clicks a perfect operation, just quicker. After using the filter to help make the selection, if you find when you view the selection on the image that you've accidentally captured something you didn't want (like the shadow behind the vase in this photo), use the Lasso or another tool to quickly deselect that area.

As you manipulate the settings for an adjustment filter, a preview of the settings displays in the Editor window. Continue tweaking the settings until the outline or area of the object you want to select becomes obvious. In this image of a flower arrangement, I played with the Threshold Level setting until the outlines of the black flowers against the white background were very clear. See 136 About an Image's Histogram for more information about the Threshold filter.

Click the OK button to close the dialog box and apply the adjustment to the selected layer.

4.

Make a Selection

With the duplicate layer still active, use one of the selection tools described in 70 About Making Selections to select the portion of the image you want. For example, you can trace the edges of an object using the Magnetic Lasso tool (see 75 Select an Object by Tracing its Edge). If the area you want to select is all one color or close to it, use the Magic Wand to select the area instead (see 77 Select Areas of Similar Color).

5.

Make Desired Edits

NOTE

To make the changes you are going to make to the image layer easy to see, hide the top layer (the duplicate layer you made the adjustment to). To hide the duplicate layer, click its eye icon on the Layers palette.

With the portion of the image you want selected, change to the original layer by clicking it on the Layers palette. If your image had only one layer, you'll want to select the Background layer.

Make the desired edits. Because you've selected the image layer and not the duplicate layer, changes you make occur only on that layer and within the selection marquee. You can make any changes you want, such as applying a filter, image adjustment, or cutting/copying the data. For this example, I copied the flower vase from its tabletop background and pasted it into a new, blank document as the start of a new composite image I had planned.

6.

Delete Duplicate Layer

You can return to the duplicate layer to select other portions of the image for adjustments. But when you're through with it, it's safe to remove it from the image. In the Layers palette, select the duplicate layer (the Background copy layer) you created in step 1 and click the Delete Layer button (the trash can icon near the top of the Layers palette) or choose Layer, Delete Layer from the menu to remove the layer.

7.

View the Result

After you're satisfied with the result, make any other changes you want and save the PSD file. Resave the result in JPEG or TIFF format, leaving your PSD image with its layers (if any) intact so that you can return at a later time and make different adjustments if you want.

View the results of edits you made using the selection. In this example, you can see the new document I opened and into which I pasted the flower vase selected from the original image. For options about making the elements you paste into another document more compatible with their new locations, see 169 Create a Composite Image.



Adobe Photoshop Elements 3 in a Snap
Adobe Photoshop Elements 3 in a Snap
ISBN: 067232668X
EAN: 2147483647
Year: 2006
Pages: 263

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