Digital Images

Size and Resolution Troubles

 

A. How does the size of an image change with the resolution?

thumb
click image to see actual size

Thumbnail

Image Size
66 x 100 pixels
.06 megapixel

Print size
0.9 x 1.3" @ 72 ppi 

Computer size
jpg = 21 kb 

Use
web thumbnail

thumb
click image to see actual size

Web Image

Image Size
264 x 400 pixels
.1 megapixel

Print size
3.67 x 5" @ 72 ppi 

Computer size
jpg = 48 kb 

Use
normal web image

thumb
click image to see actual size

Large Web Image

Image Size
480 x 727 pixels
.3 megapixel

Print size
6.67 x 10" @ 72 ppi 

Computer size
jpg = 330 kb 

Use
large web image

thumb
click image to see actual size

Print Image

Image Size
1,000 x 1,515 pixels
1.5 megapixel

Print size
6.67 x 10" @ 150 ppi 

Computer size
jpg = 1,100 kb 

Use
printing at this size

thumb
click image to see actual size

Camera Image

Image Size
2,000 x 3,029 pixels
6 megapixel

Print size
6.67 x 10" @ 300 ppi 

Computer size
jpg = 3,400 kb 

Use
Digial camera original image

 

B. Common computer sizes:

  1. Floppy disk = 1.4 mb (1,400 kb)
  2. Email attachment = 5 mb
  3. Free email folder = 500 mb
  4. Your personal network folder = 200 mb
  5. CD = 700 mb
  6. DVD = 4 gb (4,000 mb)
  7. Camera Card = 2-8 gb (2,000 - 8,000 mb)
  8. Hard Drive = 50-2,000 gb (50,000 - 2,000,000 mb)

 

C. Common resolutions

  1. Computer screen = web images = 72 ppi
  2. Laser printing = 150 ppi
  3. High quality professional print = 300 ppi

 

D. Other notes

  1. You can drop resolution, but you cannot increase it. So, scan or take pictures at higher resolution. See the resolution change image for a graphical description of this.
  2. Jpg images are compressed, so they are smaller in computer size. Tiff, bmp or images in publisher are much larger (often 10x larger) than jpgs.
  3. Scan or take pictures at high resolution if you are going to blow them up.
  4. Once you start dealing with higher resolution images, you cannot use email to send pictures.

 


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