If want to do is quickly readjust the colors of an image, using the Image > Adjust >
Autolevels gives a pretty good result. For PowerPoint presentations, I find it also generally
improves an image to click Image > Adjust > Brightness/Contrast and increase the contrast (and
perhaps the brightness as well). If you want more flexibility and control, read on.
Crop tool: you can simply drag a crop marquee (R3-C1) over a portion of an image, or preset the
width and height to fit a destination. Once the marquee is set, you can rotate or resize it. Hit Enter
to finalize your cropped selection. If you rotate the rectangular marquee, the final cropped image is
aligned with the sides horizontal and vertical.
Enlarge or reduce an image by clicking Image > Image Size. Keep the proportions constrained
and overtype any of the size values with one you prefer.
Rotate (or flip) an image by clicking Image > Rotate Canvas, and selecting an option.
You can reduce the screening effect by clicking Filter > Blur > Gaussian Blur, and selecting a
radius of 0.5 to 1.0. This will blur text and other things also, which may not be suitable. You can
use the marquee tool (R1-C1) to select and apply a gaussian blur to only a selected area.
Adjusting the tonal range. The tonal range of an image represents the amount of contrast.
Choose Image > Adjust > Levels, and make sure that the Preview option is checked.
The histogram tells you the spread of pixels corresponding to various levels of lightness.
The slider triangles at the bottom of the histogram represent the shadows (black triangle),
highlights (white triangle), and midtones or gamma (gray triangle). If your image had colors
across the entire brightness range, the graph would extend across the full width of the
histogram, from black triangle to white triangle. A clump toward the center indicates there are
no very dark or light colors.
It is a good practice to drag the bounding sliders to fit the range of darkest and lightest extent of
the range, and select OK to spread the range out to a more complete range.
Removing a color cast. Some images contain color casts (imbalances of color), either in the
original or due to scanning (e.g. an image may be too red). This can be done permanently by
selecting Image > Adjust Levels. A Color Balance adjustment layer, however, lets you edit an
image as many times as you like without permanently changing the original pixel values. After you
see the printed copy you can make additional changes to the image, if necessary.
To create such a layer, choose Layer > New Adjustment Layer > Color Balance. Click OK
to create the adjustment layer and to display the Color Balance Layer dialog box.
Be sure there is a check in the Preview option, and adjust the sliders to correct the color balance
to taste. Click OK to apply the changes. Notice that a Color Balance layer has appeared in the
Layers palette.
Click the eye icon next to the Color Balance layer in the Layers palette to hide/show the layer.
You’ll see the difference between the adjusted colors and the original colors.
When you double-click an adjustment layer in the Layers palette, the corresponding dialog box
appears, where you can edit the values of the adjustment layer.
Replacing colors in an image. Use the Replace Color command to create temporary masks based
on specific colors and then replace these colors. Masks let you isolate an area of an image, so that
changes affect only the selected area and not the rest of the image.
If you have layers, select the background layer in the Layers palette.
Select the rectangle marquee tool (R1-C1), and then drag a selection around the area
containing the color you want to replace (zoom if helpful).
Choose Image > Adjust > Replace Color to open the Replace Color dialog box.
Use the eyedropper tool to select the area of color that will be masked and replaced with a new
color. The first eyedropper tool selects a single color, the eyedropper-plus tool may be used to
add colors to a selection, and the eyedropper-minus tool may be used to subtract colors from a
selection. Use any combination of these eyedroppers until the area you want to change is
highlighted in white in the dialog box.
You may slide the Fuzziness control to adjust the degree to which related colors are included in
the mask.
In the Transform area of the Replace Color dialog box, drag the Hue , Saturation, and
Lightness sliders to modify the selected color area. Hue is color, saturation is the purity of the
color, and lightness is how much white or black is in the image.
Adjusting saturation with the sponge tool. When you change the saturation of a color you adjust
its strength or purity. The sponge tool is useful in letting you make subtle saturation changes to
specific areas of an image.
Select the sponge tool (Alt-click R7-C2 of the toolbox).
To increase the saturation of an area, choose Saturate in the Options area at the top. To set the
intensity of the saturation effect to a high saturation adjust the Pressure to a high value (90%).
To decrease the saturation of an area, choose Desaturate in the Options area.
Select a feathered brush from the Brushes palette.
Drag the sponge back and forth over an area to modify the saturation of their color.
You can undo using Ctrl-z if you were overzealous and try again..
Adjusting lightness with the dodge tool. The dodge tool is based on the traditional
photographer’s method of blocking (dodging) light during an exposure to lighten an area of an
image.
Select the dodge tool (Alt-click R7-C2 of the toolbox).
Choose Highlights from the menu in the Tool Options palette (top of area), to adjust only the
highlights, etc. Set Exposure to 50%.
Select a medium, feathered brush and drag it over the area to adjust.
You can undo using Ctrl-z if you were overzealous and try again..
Removing unwanted objects. Using the rubber stamp tool, you can remove an object or area by
“cloning” a nearby area of the image over the area you want to eliminate. You may first want to
use the zoom tool (R11-C2) to magnify an area to work in.
Select the rubber stamp tool (R5-C1 ) in the toolbox, and make sure that the Aligned option in
the Rubber Stamp Options palette at the top is deselected.
Select an appropriate brush size in the Options palette (cloning is best if a feathered brush is
used).
Center the rubber stamp tool over the area you want to clone, and hold down Alt key as you
click to sample or copy that part of the image. Make sure that the area you sample blends well
with the area around the object you are removing.
Drag the rubber stamp tool over the area to be eliminated to paint over it with a copy of the area
you just sampled. Notice the crosshair that follows your cursor as you paint; it represents the
point from which the rubber stamp tool is cloning.
Replacing part of an image. Suppose the sky is fairly drab and overcast in a photograph, you can
replace it with a more interesting sky from another file.
Begin by selecting the current sky. Select the magic wand tool (R2-C2) ). Click to select part of
the sky. If the sky isn’t contiguous, hold down Shift, and click the rest of the sky to select it.
Open a file with good sky and clouds (Clouds.psd is one provided by Adobe).
Choose Select > All; then choose Edit > Copy. Close the Clouds.psd file.
Choose Edit > Paste Into to paste the clouds into the current selection. Notice that a new layer
has been added to the Layers palette.
Select the move tool (R1-C1) ), and drag the clouds into the position you want.
You may
Autolevels gives a pretty good result. For PowerPoint presentations, I find it also generally
improves an image to click Image > Adjust > Brightness/Contrast and increase the contrast (and
perhaps the brightness as well). If you want more flexibility and control, read on.
Crop tool: you can simply drag a crop marquee (R3-C1) over a portion of an image, or preset the
width and height to fit a destination. Once the marquee is set, you can rotate or resize it. Hit Enter
to finalize your cropped selection. If you rotate the rectangular marquee, the final cropped image is
aligned with the sides horizontal and vertical.
Enlarge or reduce an image by clicking Image > Image Size. Keep the proportions constrained
and overtype any of the size values with one you prefer.
Rotate (or flip) an image by clicking Image > Rotate Canvas, and selecting an option.
You can reduce the screening effect by clicking Filter > Blur > Gaussian Blur, and selecting a
radius of 0.5 to 1.0. This will blur text and other things also, which may not be suitable. You can
use the marquee tool (R1-C1) to select and apply a gaussian blur to only a selected area.
Adjusting the tonal range. The tonal range of an image represents the amount of contrast.
Choose Image > Adjust > Levels, and make sure that the Preview option is checked.
The histogram tells you the spread of pixels corresponding to various levels of lightness.
The slider triangles at the bottom of the histogram represent the shadows (black triangle),
highlights (white triangle), and midtones or gamma (gray triangle). If your image had colors
across the entire brightness range, the graph would extend across the full width of the
histogram, from black triangle to white triangle. A clump toward the center indicates there are
no very dark or light colors.
It is a good practice to drag the bounding sliders to fit the range of darkest and lightest extent of
the range, and select OK to spread the range out to a more complete range.
Removing a color cast. Some images contain color casts (imbalances of color), either in the
original or due to scanning (e.g. an image may be too red). This can be done permanently by
selecting Image > Adjust Levels. A Color Balance adjustment layer, however, lets you edit an
image as many times as you like without permanently changing the original pixel values. After you
see the printed copy you can make additional changes to the image, if necessary.
To create such a layer, choose Layer > New Adjustment Layer > Color Balance. Click OK
to create the adjustment layer and to display the Color Balance Layer dialog box.
Be sure there is a check in the Preview option, and adjust the sliders to correct the color balance
to taste. Click OK to apply the changes. Notice that a Color Balance layer has appeared in the
Layers palette.
Click the eye icon next to the Color Balance layer in the Layers palette to hide/show the layer.
You’ll see the difference between the adjusted colors and the original colors.
When you double-click an adjustment layer in the Layers palette, the corresponding dialog box
appears, where you can edit the values of the adjustment layer.
Replacing colors in an image. Use the Replace Color command to create temporary masks based
on specific colors and then replace these colors. Masks let you isolate an area of an image, so that
changes affect only the selected area and not the rest of the image.
If you have layers, select the background layer in the Layers palette.
Select the rectangle marquee tool (R1-C1), and then drag a selection around the area
containing the color you want to replace (zoom if helpful).
Choose Image > Adjust > Replace Color to open the Replace Color dialog box.
Use the eyedropper tool to select the area of color that will be masked and replaced with a new
color. The first eyedropper tool selects a single color, the eyedropper-plus tool may be used to
add colors to a selection, and the eyedropper-minus tool may be used to subtract colors from a
selection. Use any combination of these eyedroppers until the area you want to change is
highlighted in white in the dialog box.
You may slide the Fuzziness control to adjust the degree to which related colors are included in
the mask.
In the Transform area of the Replace Color dialog box, drag the Hue , Saturation, and
Lightness sliders to modify the selected color area. Hue is color, saturation is the purity of the
color, and lightness is how much white or black is in the image.
Adjusting saturation with the sponge tool. When you change the saturation of a color you adjust
its strength or purity. The sponge tool is useful in letting you make subtle saturation changes to
specific areas of an image.
Select the sponge tool (Alt-click R7-C2 of the toolbox).
To increase the saturation of an area, choose Saturate in the Options area at the top. To set the
intensity of the saturation effect to a high saturation adjust the Pressure to a high value (90%).
To decrease the saturation of an area, choose Desaturate in the Options area.
Select a feathered brush from the Brushes palette.
Drag the sponge back and forth over an area to modify the saturation of their color.
You can undo using Ctrl-z if you were overzealous and try again..
Adjusting lightness with the dodge tool. The dodge tool is based on the traditional
photographer’s method of blocking (dodging) light during an exposure to lighten an area of an
image.
Select the dodge tool (Alt-click R7-C2 of the toolbox).
Choose Highlights from the menu in the Tool Options palette (top of area), to adjust only the
highlights, etc. Set Exposure to 50%.
Select a medium, feathered brush and drag it over the area to adjust.
You can undo using Ctrl-z if you were overzealous and try again..
Removing unwanted objects. Using the rubber stamp tool, you can remove an object or area by
“cloning” a nearby area of the image over the area you want to eliminate. You may first want to
use the zoom tool (R11-C2) to magnify an area to work in.
Select the rubber stamp tool (R5-C1 ) in the toolbox, and make sure that the Aligned option in
the Rubber Stamp Options palette at the top is deselected.
Select an appropriate brush size in the Options palette (cloning is best if a feathered brush is
used).
Center the rubber stamp tool over the area you want to clone, and hold down Alt key as you
click to sample or copy that part of the image. Make sure that the area you sample blends well
with the area around the object you are removing.
Drag the rubber stamp tool over the area to be eliminated to paint over it with a copy of the area
you just sampled. Notice the crosshair that follows your cursor as you paint; it represents the
point from which the rubber stamp tool is cloning.
Replacing part of an image. Suppose the sky is fairly drab and overcast in a photograph, you can
replace it with a more interesting sky from another file.
Begin by selecting the current sky. Select the magic wand tool (R2-C2) ). Click to select part of
the sky. If the sky isn’t contiguous, hold down Shift, and click the rest of the sky to select it.
Open a file with good sky and clouds (Clouds.psd is one provided by Adobe).
Choose Select > All; then choose Edit > Copy. Close the Clouds.psd file.
Choose Edit > Paste Into to paste the clouds into the current selection. Notice that a new layer
has been added to the Layers palette.
Select the move tool (R1-C1) ), and drag the clouds into the position you want.
You may
No comments:
Post a Comment