Transcript Screen and Image Resolution

Screen and Image Resolution
2.01 Investigate graphic image design.
Types of Images
Clip Art – premade graphics that are
available online and in many software
packages; may be vector or raster.
• Photographs – raster images that contain
millions of colors.
• Art Work – computer created drawings or
paintings; may be raster or vector.
Which type of image is appropriate?
• Select images that reflect the purpose and
theme of the document.
• Use images to convey meaning and
communicate, not to decorate.
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1.02 Investigate image editing.
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The quality of an image is
dependent upon two factors:
Resolution
2. Aspect Ratio
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1.02 Investigate image editing.
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Image Resolution
Measured in PPI, or pixels per inch.
• PPI is the numbers of pixels contained in one
inch.
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The higher the PPI, the better the quality.
− The higher the PPI, the larger the file size.
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Match the quality to the delivery method.
Most monitors can only display 72 PPI, so
images that will be displayed on a monitor do
not need a higher PPI.
− Printers can print in much more detail so
printed images need to contain more pixels per
inch.
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Types of Resolution
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PPI – pixels per inch
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The number of pixels in an image.
DPI – dots per inch printed by a printer.
Dots of ink or toner in a printed image
− The lower the DPI of a printer, the less detailed the
image will be.
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150 PPI is sufficient for most personal desktop printers.
300 PPI is better for high-quality images printed on
more sophisticated printers.
1.02 Investigate image editing.
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Monitor Resolution
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Also measured in PPI.
Refers to the number of pixels per inch displayed on a
monitor.
The higher the resolution, the higher the level of detail
As resolution is increased on the monitor, detail is
emphasized and image size is reduced
1024x768
Industry Standard
640x480
1.02 Investigate image editing.
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Aspect Ratio
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Aspect Ratio –
relationship of an
object’s width to its
height
What’s the answer?
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An original image
that is 1”x 1” has a
resolution of 100 PPI
What is the effect on
the resolution of
enlarging the image
to 2”x 2”?
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1.02 Investigate image editing.
What happens to the
image quality?
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Resizing a Raster Image
A small image that is
enlarged is easily
distorted.
 Pixels are not added, just
enlarged
 Better to start with a large
image and make it smaller
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File size will remain the same
An image must be edited to
reduce file size.
1.02 Investigate image editing.
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