Graphics&DesignCorrection and Adjustment - Creative: colour & tone, dust & marks, sharpTech: Gamma, Histograms, & Convolution

Graphics&Design

colour & contrast

• levels• curves• hue & saturation• channel mixer

Graphics&Design

gamma curves

Equivalent to Brightness & Contrast

‘brightness’ - loss of highlight detail

‘darken’ - loss of shadow detail

‘increased contrast’ - loss of both

Graphics&Design

gamma curves & levels

Improved using Curves

‘brightness’ - loss of highlight detail

‘gamma curve’ - retains shadow & highlight detail

Levels histogram - sample with ‘eyedroppers

Graphics&Design

dust & scratches

Original

‘Old Image’

damaged with scratches and other age marks

Partial restoration with Dust & Scratches filter. Some loss of definition - (note blurred tie.)

Complete restoration with ‘Heal’ brush. A similar effect could be obtained from the Stamp tool

Graphics&Design

Technical - Unsharp Mask

Unsharp mask - masks the ‘unsharp’ bits

• uses a ‘convolution’ filter to detect edges

•Uses the edges to make mask

•Increases contrast in masked area

Original Convolution Unsharp masking Custom filter