You are scanning 4 inch times 5 inch physical phatas to make

You are scanning 4 inch times 5 inch physical phatas to make digital images. In this exercise, the field of view is specified relative to the photo size rather then to the objects in the photo. a) If you want to scan the whole photo with 24 bits per color pixel at 2400 pixcls per inch, how big will the image file be? b) If you want to scan the photo for use on a webpage thet limits the width and height of the photo to a maximum of 800 pixels cach, what is the maximum number of pixels per inch you can use? c) You are scanning your photo according to the limits specified in part (b) but you want to use the full 2400 pixels/inch resolution on a small area of your photo. What is the width of the maximum area you can scan at 800 pixels/inch and still meet the restrictions of (b)?

Solution

A)

- For example, if your camera has given you a 1200x1600 pixel image (just under 2 mega-pixels) and you want 300 ppi for printing, then you will get a 4\" x 5 1/3\" image (1200/300 x 1600/300).

- But if you want 300 ppi, you will need 2400 x 3000 pixels (7.2 MP). Notice that to make the linear resolution double, it takes four times the MP size of the image.

B)

-If we scan a pic in web page 800 pixels each. The width is 6000 pixels and the height is 4000 pixels. So the pixels per inch is 7.5*5.0 inches.

C)

-scan resolution-2400dpi

6*4 image size-14400x9600

Pixel count-138,240,000

24 bit RGB color-414,720,000

memory 8 bit-138,240,000

size in bytes-17,280,000