36 Making Image Adjustments
• via PhotoFix, a studio environment for managing and applying
cumulative adjustments (non-destructive).
• via Image>Adjust, on a filter layer (non-destructive).
• via Image>Adjust, on a standard layer (destructive).
Here’s a summary of the available PhotoPlus image adjustments.
• Levels: Displays a histogram plot of lightness values in the
image, from which you can adjust the tonal range by shifting
dark, light, and gamma values.
• Curves: Displays lightness values in the image using a line
graph, and lets you adjust points along the curve to fine-tune
the tonal range.
• Brightness/Contrast: Brightness refers to overall lightness or
darkness, while contrast describes the tonal range, or spread
between lightest and darkest values.
• Shadow/Highlight/Midtone: Controls the extent of shadows,
highlights, and contrast within the image.
• Hue/Saturation: Hue refers to the colour’s tint—what most of
us think of as rainbow or spectrum colours with name
associations, like "blue" or "magenta". Saturation describes the
colour’s purity—a totally unsaturated image has only greys.
Lightness is what we intuitively understand as relative darkness
or lightness—ranging from full black at one end to full white at
the other.
• Colourize: Lets you recolour an image using Hue, Saturation,
and Lightness.
• Vibrance: Boosts low-saturation colours in your image, while
high-saturation colours are less affected.