Outline the steps to adjust images tonal range and colour
values using imaging software.
In This Chapter, youll learn on: Identify the tools that
manipulates the following: o colour levels o brightness o contrast
o shadows o mid-tones o highlights Adjust the images colour levels,
brightness, contrast and highlights to improve its aesthetic
appeal.
Colour and tonal adjustments There are powerful tools in
Photoshop that can enhance, repair, and correct the colour and
tonality (lightness, darkness, and contrast) in an image. Most of
the adjustments is accessible via Image > Adjustments. However
we are introducing adjustments via layers. To do this, go to Layers
> New Adjustment Layer or
Colour and tonal adjustments Select which adjustment you need
on the on the layers palette (accessible in Window/
Adjustment)
Colour and tonal adjustments It will create an additional layer
that contains the adjustment while preserving the original
image.
Colour and tonal adjustments The adjustment panel will switch
to a new layer with sliders controls for you to fine tune your
settings to your image. Some of the common tools for tonal and
colour adjustments are Brightness/Contrast, Levels, Curves,
Vibrance, Hue/Saturation, and Colour balance. Original Image before
adding any adjustment layers
Colour and Tonal Adjustment: Brightness / Contrast The
Brightness/Contrast adjustment lets you make simple adjustments to
the tonal range of an image. Moving the brightness slider to the
right increases tonal values and expands image highlights, to the
left decreases values and expands shadows. The contrast slider
expands or shrinks the overall range of tonal values in the image.
By adjusting the brightness and contrast, you can make the picture
brighter
Colour and Tonal Adjustment: Levels The outer two Input Levels
sliders map the black point and white point to the settings of the
Output sliders. By default, the Output sliders are at level 0,
where the pixels are black, and level 255, where the pixels are
white. With the Output sliders in the default positions, moving the
black input slider maps the pixel value to level 0 and moving the
white point slider maps the pixel value to level 255. The remaining
levels are redistributed between levels 0 and 255. This
redistribution increases the tonal range of the image, in effect
increasing the overall contrast of the image. By adjusting the
levels, you can also increase the overall contrast between the
black and white
Colour and Tonal Adjustment: Curves Using curves to obtain
colour balance is best for global colour shifts because it
compresses/stretches the tonal values across the image. In other
words, it achieves an over-all shift in the shadows, midtones, and
highlights. For colour correction in a specific tonal range you can
use the Colour Balance tool. Adjusting the curves achieve an
overall midtones/shadows/highlights shifting
Colour and Tonal Adjustment: Vibrance Vibrance adjusts the
saturation so that clipping is minimized as colours approach full
saturation. This adjustment increases the saturation of
less-saturated colours more than the colours that are already
saturated. Vibrance also prevents skintones from becoming over
saturated. Adjusting the Vibrance can make the colours of the image
richer or vice versa.
Colour and Tonal Adjustment: Hue / Saturation Hue/Saturation
lets you adjust the hue, saturation, and lightness of a specific
range of colours in an image or simultaneously adjust all the
colours in an image. This adjustment is especially good for
fine-tuning colours in a CMYK image so that they are in the gamut
of an output device. Adjusting the hue/saturation can also help
create special colour cast/effects.
Colour and Tonal Adjustment: Colour Balance Colour Balance is a
general term referring to the fine balancing of the colours in
visible light and it is strongly tied to the white balance. White
Balance refers specifically to the way the Colour Balance is
adjusted so white objects will appear white under any lighting
conditions. The human eye is well adapted, in connection with our
brains, to adjust the colour information it receives so that
objects we know to be white, appear white. If this did not happen,
and we processed light as it is, "white" objects would look yellow
under tungsten light, green under fluorescents, etc. By adjusting
the colour balance, you can alter the white balance to give the
image a different look.