2.01D Investigate graphic image design.

Image Resolution

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.

Types of Images

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.

The quality of an image is dependent upon two factors:

1. Resolution2. Aspect Ratio

Aspect Ratio

Resolution

Image Resolution• Resolution is the amount of detail (or data)

stored for an image.• The higher the resolution, the higher the

level of detail in the image.• Resolution is measured in PPI, or pixels per

inch (the number of pixels contained in one inch).− The higher the PPI,

• the more data that is stored and the better the quality.

• the larger the file size.

• Image editing software can be used to change the resolution of an image.

Image Output Methods• Images can be viewed in two ways:

− On a screen or monitor− By printing it on paper

• Monitors− The display resolution on monitors is also measured in

PPI.− Monitors are low resolution devices, most display 72 PPI.

• Printers− Printers create output by placing ink or toner on paper.− The resolution at which printers can print is measured in

Dots Per Inch (DPI).− Printers are high resolution devices in order to print

images clearly without pixilation or blurriness.

Match The Image Quality To The Delivery Method.

• Images that will be displayed on a monitor do not need a high resolution.− Using a low resolution means smaller file sizes.− Images with small file sizes load quicker.

• Images that will be printed need a higher resolution. − Images with 150 PPI are sufficient for printing on

most personal desktop printers.− Images with 300 PPI are better for printing on

more sophisticated printers and will produce higher-quality photographs.

Aspect Ratio

Aspect Ratio – relationship of an object’s width to its height

Aspect Ratio

Resolution

What’s the answer? Start Here

An 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”?

It becomes 50 pixels per inch. The same number of pixels is still in the image but the display area is larger

What happens to the image quality? If the resolution is reduced by half, the image

quality is also reduced.

(continued)

What’s the answer? Continued

How will this image look when printed?You will see pixilation because each pixel in

the image must cover a larger space on the screen.

Resizing a Raster ImageA small image that is

enlarged is easily distorted.

Pixels are not added, just enlarged

Better to start with a large image and make it smallerFile size will remain the

sameAn image must be edited in

a photo editing program to reduce file size.