Graphics Programs Reference
In-Depth Information
The insets in Figure 3.1 and Figure 3.2 show that more megapixels means you
can digitally zoom in much further and still have good quality. The cat on the
mat in Figure 3.1 is far more blurry and noisy compared with Figure 3.2.
On the downside, greater numbers of pixels consume more RAM and take up
more file storage space. If you are shooting photos for the Web but not for print,
you can get away with using fewer megapixels. However, resampling large images
down to the desired size will always result in higher-quality photos compared to
shooting fewer megapixels to start with. The adage that
you get what you pay for
rings true for digital cameras.
O
More pixels gener-
ally mean more
detail can be cap-
tured and with less
noise.
selecting the Pixel Aspect Ratio
If you are creating output for the Web or for print, then you will always use square
pixels (see Figure 3.3).
FIGURe 3.3
Square pixels
shown at maximum magnification
O
The Extended version of Photoshop can do video editing and people can easily
get confused when dealing with video files having non-square-pixel aspect ratios.
It's really very simple, however. Choose the pixel aspect ratio on the View menu
according to the video format you are using.
Figure 3.4 shows pixels that are 1.5 times as wide as they are tall according to
the DVCPRO HD 1080 standard. At 100% magnification, an image shown with
the wrong pixel aspect ratio would appear either too narrow or too wide. The
amount of stretching in standards D1/DV NTSC or D1/DV PAL is very subtle
because these standards have aspect ratios closer to square.
in photoshop CS6
extended you can
paint, clone, and
even add text over
multiple frames of
a video sequence
using the Movie
paint feature.
Select Layer
a
Video Layer
a
new Video Layer
From File... and
your video clip will
be imported as a
single video layer
that you can paint on
non-destructively.
FIGURe 3.4
Pixels with an aspect
ratio of 1.5 shown at maximum magnification
