CSC/FAR 020, Computer Graphics, October 5 and 12,

2011Dr. Dale E. Parson

http://faculty.kutztown.edu/parsonOutline for week 6Retouch & Related

Exposure

• Retrieve retouch.zip from Parsons/Outbox.• Open ParsonShadow.psd.

• Note face in hat’s shadow.

• Image -> Adjustments -> Shadow / Highlights• Shadows brightens the shadow areas.

• Amount increases luminance, keeps color ratios intact.• Radius gives number of pixels measured for correction.• Tonal width gives range of pixel values used for correction.

• Highlights darkens the highly lit areas.

Exposure Continued

• Midtone contrast sets amount of contrast in middle-light areas.

• Black and white clipping set cutoff levels.• Color correction boosts or drops saturation.• Try effect on entire image.

• Note loss of contrast in rock shadows.

• Try effect on figures after magnetic lasso selection of figures only.

Photo Filters

• Add a Photo Filter Adjustment Layer.• You might think cooling would be appropriate

for the desert, but . . .• Warming or red filtering works better with the

rocks.• Density adjusts the filter’s visual thickness.• Try adjusting opacity and fill of this

adjustment layer as well.

Correcting Overexposure in an Adjustment Layer

• Delete the previous filter adjustment layer.• Add a Levels adjustment layer.

• Use Blending Mode Multiply to darken.• Use Blending Mode Screen to lighten.

• You can add multiple Adjustment Layers -> Levels -> Blending Mode Multiply for successive approximation. Tweak opacity of final layer.

• Merge Adjustment Layers when you are satisfied.

Correcting Backlit Photos

• Close Photoshop files without saving.• In Bridge, select ParsonUnshavedDarkS210.

• Do NOT open in Photoshop.

• Edit -> develop settings -> camera raw defaults• Double click opens with camera raw.• Fill Light slider corrects for back lighting.• Open in Photoshop, compare to

ParsonUnshavedDarkS210 Copy (original).

Correcting Backlit Photos – Manual Alternative

• Edit -> Develop settings -> Clear Settings in Bridge.• Open ParsonUnshavedDarkS210 in Photoshop.• Add a Levels Adjustment Layer, adjust upper and

midrange sliders for exposure.• To darken background, add a layer mask, Fill with

Black, and then Brush with White to remove portions of the mask to lighten areas.

• Filter -> Render -> Lighting Effects to add spotlights, etc.

Lens Blur Filter

• Reopen ParsonShadow (desert photo), Duplicate Background Layer.

• Add a Layer Mask, use Gradient tool to apply a back/white foreground/background gradient.

• Verify Layer Mask, then Disable.• Select the layer’s image thumbnail, then use

Filter -> Blur Lens to add blurring.• Set blur filter to layer mask as reference.

Motion Blur and Smart Image

• Start over with a Duplicate Layer of ParsonShadow.• Filter -> Convert for Smart Filter to create a filter

with parameters you can tweak after you apply the filter.

• Filter -> Motion Blur, set the parameters.• Paint with Black or Fill with Black in the Smart Filters

Mask to unblur a section.• Double Click the Motion Blur entry below the mask

to recompute the blur parameters.

Smart Gaussian Blur

• Start over with a Duplicate Layer of ParsonShadow.• Filter -> Convert for Smart Filter to create a filter

with parameters you can tweak after you apply the filter.

• Select an area before blurring, then Invert selection to select the surrounding image.

• Filter -> Blur -> Gaussian Blur.

Removing Spherical andChromatic Lens Aberrations

• Open, Duplicate Layer for ParsonUnshavedD90.jpg.

• Note spherical aberration.

• Filter -> Convert for Smart Filters.• Use Filter -> Distort -> Lens Corrections to

remove Spherical Aberration.• Use Scale to restore foreground image size.

• Lens Correction also removes Chromatic Aberration.

Sharpen Focus

• Open, Duplicate Layer for ParsonFocus.jpg.• Note out of focus professor.

• Select professor’s pixels.• Filter -> Sharpen -> Smart Sharpen.

• We won’t make a smart layer -- too time consuming.

• Amount 213%, pixels 10 seems in the ballpark.• Toggle Preview on and off.• “Pixels” says where to look for “stray photons.”• “Amount” is how far to move them.

Unsharp Mask

• Open, Duplicate Layer for ParsonFocus.jpg.• Note out of focus professor.

• Select professor’s pixels.• Filter -> Sharpen -> Unsharp Mask.

• We won’t make a smart layer -- too time consuming.

• Amount 223%, pixels 4.6 seems tolerable.• Toggle Preview on and off.• I don’t like this one as much.

Duplicating Color Range of one Document in Another

• Close All Photoshop, then from Bridge open ParsonShadow then ParsonFocus.

• Duplicate Layer in ParsonFocus (target).• Image -> Adjustments -> Match Color.• Use ParsonShadow as the source.• Vary parameters to temper the effect.

Clone Stamp AcrossLayers and Images

• Open fresh copies of ParsonShadow and RohrbachCenter.

• Using multiple layers, Clone Stamp from one to another.

• Using multiple image files, Clone Stamp from one to another.

Color Replacement

• In ParsonFocus -> Layer -> Copy Background.• Select the boring, washed-out shirt.• Image -> Adjustments -> Replace Color.• Use eyedropper to select source color.• Use Color Pickers to tune input-to-output.• Use Fuzziness to set color tolerance for input.• You can make teeth whiter, beards darker.

“Softening Focus”

• Filter -> Blur -> Surface Blur can soften focus.• Remove unwanted blemishes.

• This also works with smart Filters.• You can paint away the effect with a layer

mask.• Test parameters on ParsonOnWhiteD90.• It’s like putting on 10 pounds of makeup!

Nip / Tuck

• ParsonUnshavedD90 -> Duplicate Layer• Healing Brush cleans up gray area under eye.• It combines Clone Stamp usage with using

pixel colors from area being healed.• Select an Ellipse on the forehead, then use

Patch Tool to create a Third Eye.• The Spot Healing Brush is a wrinkle remover.

• It copies and merges pixels from a parallel stroke.

Red Eye Repair

• Use Image -> Adjustments -> Replace Color to give me a Red Eye.

• Use Pupil Size just over 50%, Darken just under 50%.

• We will do the classic Halloween assignment again.