11 masking & sharpening g

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Masking Masking

Techniques and materials used to control theTechniques and materials used to control thedevelopment of art bydevelopment of art by protecting protecting a desired areaa desired areafrom changefrom change

UsedUsed totoenhanceenhanceimageimagequalityquality

Masking Masking

Like masking tape when house paintingLike masking tape when house painting

Protective Pattern Protective Pattern

Darkest areasDarkest areas most protected most protected Gray areasGray areas Partially protected Partially protected White areasWhite areas unprotected unprotected

Digital Masking Digital Masking

Consists of a grayscaleConsists of a grayscalechannelchannel called an called an alpha channel alpha channel can be displayed as a ruby can be displayed as a ruby

overlay overlay so underlying image can beso underlying image can beseen through the maskseen through the mask

Channel Mask Channel Mask


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Masking Masking - - Shades of gray Shades of gray

Represent areas ofRepresent areas ofpartial protectionpartial protectioncorresponding with thecorresponding with theeve o grayeve o gray Often masking is used Often masking is used

to apply varying levels to apply varying levels of transparency to a of transparency to a layer or image layer or image

Apply Apply Image Image

Layer Mask Layer Mask Layer Mask Layer Mask

La er La er Mask Mask

Selections and Quick Mask Selections and Quick Mask


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HOW UNSHARP MASKING HOW UNSHARP MASKING WORKS WORKS

the pixel is changed the pixel is changed

by the by the OPPOSITE OPPOSITE amount amount of the difference between of the difference between

the original and blurredthe original and blurredpixelspixels

multiplied by the usermultiplied by the user- -defined "percentage"defined "percentage"

UNSHARP MASKING PROBLEMS UNSHARP MASKING PROBLEMS

looklook artificialartificial

Too Much Too Much cancan

or bizarreor bizarre

accentuateaccentuateproblemsproblemsin originalin originalimageimage

HALOS HALOS Blips Blips that appear on either that appear on either side of tonal shifts with side of tonal shifts with unsharp unsharp masking masking

Mach Bands Mach Bands

An optical illusionAn optical illusion bands of different brightness on either side of bands of different brightness on either side of

a gra ent t at are not present n or g na a gra ent t at are not present n or g na image image

ALIASING ALIASING Hard diagonal edges get jaggy Hard diagonal edges get jaggy

like a dark building against a light like a dark building against a light sky sky

Lower image resolution Lower image resolution more more potential aliasing potential aliasing

SPECKLING AND MOTTLING SPECKLING AND MOTTLING

Images Images often contain random sample points that often contain random sample points that dont match their surroundings dont match their surroundings

noise/grain noise/grain irregularities inirregularities inoriginaloriginal imageimage


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SPECKLING AND MOTTLING SPECKLING AND MOTTLING

Sharpening can Sharpening can

accentuateaccentuateirregularitiesirregularities

destroy smoothdestroy smoothgradationsgradations

Photoshop Photoshop Unsharp Unsharp Masking Masking

Three Three variables variables

Amount Amount

Each Each increases or decreases sharpening in increases or decreases sharpening in different areas and situations different areas and situations

Radius Radius

Threshold Threshold

RADIUS RADIUS

Set Set Radius first Radius first

Controls Controls how wide the blips are on each side how wide the blips are on each side of an edge, in sample points of an edge, in sample points

Large values make for wide blips Large values make for wide blips

big halos, lots of sample points involvedbig halos, lots of sample points involved

Small Small values make smaller blips values make smaller blips

larger radius means more sharpening larger radius means more sharpening

RADIUS RADIUS

InIn excessexcess Prime Prime culprit in most sharpenin culprit in most sharpenin - -related related

problems problems

DependentDependent on on imageimage resolutionresolution Higher resolution images Higher resolution images need to have need to have

larger radius larger radius

Radius Radius Value Value

Big Big enough to enough to provide provide sharpening effect sharpening effect

Not Not so bi as to ive so bi as to ive im ression im ression of of artificiality artificiality

big halosbig halos

AMOUNT AMOUNT

Control the volume, or amplitude Control the volume, or amplitude

adjusts how intense the blips are on eachadjusts how intense the blips are on eachside of a tonal shiftside of a tonal shift

how muchhow much tonaltonal differences aredifferences areaccentuatedaccentuated

Large values make large tonal differences Large values make large tonal differences where edges meet where edges meet


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AMOUNT AMOUNT

Small Small values make less significant blips values make less significant blips

Amount settin of 200 ercent Amount settin of 200 ercent

good starting pointgood starting point

is set too high is set too high

can get an artificialcan get an artificial look look

THRESHOLD THRESHOLD Specifies how far apart Specifies how far apart adjacent tonal values adjacent tonal values have to be have to be before before filter filter does anything to them does anything to them

If If set to three set to three

adjacent sample points are of values 122 and 124 adjacent sample points are of values 122 and 124

a difference of twoa difference of two

theyre unaffected by sharpeningtheyre unaffected by sharpening

on a scae o to on a scae o to

THRESHOLD THRESHOLD

Low Low- -contrast contrast areas areas- -those with smooth those with smooth gradations gradations

arent affected; the gradations stay smooth arent affected; the gradations stay smooth

key to avoidingkey to avoiding

mottling, speckling etcmottling, speckling etc

High values result in less sharpening High values result in less sharpening

Smart Sharpen Smart Sharpen First Sharpen FilterFirst Sharpen Filtermenu change in 14menu change in 14yearsyearsRemove optionsRemove options Lens Blur Lens Blur Motion Blur Motion Blur

Each option triggers a different algorithm thatEach option triggers a different algorithm that

Photoshop uses to remove these specific types ofPhotoshop uses to remove these specific types ofblursblurs

Removing Gaussian Blur Removing Gaussian Blur

Same as regularSame as regular unsharpunsharp maskingmasking Except: Except:

Better control overBetter control overthresholdthreshold shadow tab shadow tab highlight tab highlight tab

More AccurateMore Accurate modemode

Advanced More Accurate Mode Advanced More Accurate Mode

Uses stateUses state- -ofof--thethe--art edge detectionart edge detectionalgorithms and a sophisticatedalgorithms and a sophisticated deconvolvingdeconvolvingmethod to remove blurmethod to remove blur CPU intensive CPU intensive Amount percentage values will need to beAmount percentage values will need to be


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Removing Lens Blur Removing Lens Blur

Removes lens blur while finding edges andRemoves lens blur while finding edges andnot creating obvious halosnot creating obvious halos image blurs are often caused by a image blurs are often caused by a

com nat on o actors com nat on o actors Some images may benefit from Lens blur Some images may benefit from Lens blur

option option useful for images with fine detailuseful for images with fine detail

Removing Motion Blur Removing Motion Blur

Directional blur removal toolDirectional blur removal tool

option to option to choose choose angle angle

Advanced Mode Advanced Mode Advanced Mode Advanced Mode

AllowsAllows individualindividual tonality sharpness settingstonality sharpness settings Midtones Midtones, Shadows and Highlights , Shadows and Highlights Tonal WidthTonal Width controls which tonal values will be affected by controls which tonal values will be affected by

the reduction in sharpness the reduction in sharpness Higher value greater range affectedHigher value greater range affected

RadiusRadius Controls size of area affected Controls size of area affected

Higher valueHigher value larger arealarger area

Advanced Mode Advanced Mode

AllowsAllows individualindividual tonality sharpness settingstonality sharpness settings Midtones Midtones, Shadows and Highlights , Shadows and Highlights

Fade AmountFade Amount Controls Controls sharpening sharpening strength strength

higherhigher thisthis setting = less sharpeningsetting = less sharpening

Tutorial Tutorial - - Smart Sharpen Smart Sharpen

http://www.youtube.com/watch?v=opUaPvOyOIohttp://www.youtube.com/watch?v=opUaPvOyOIo

11 masking & sharpening g

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