- It stands for "Dots Per Inch".
- It is used to measures the resolution of image both on screen and in print.
Why use DPI:
- In computer, it is used to measure of the sharpness on display screen.
- In printing, it is usual measure of printed image quality on the paper.
- Choosing the higher print quality reduces the speed of printing each page.
Measurement:
- A 600 dpi printer can print 600 dots both horizontally and vertically per inch, it actually prints 360,000 (600 X 600) dots per square inch.
- Most monitors have a native resolution of 72 or 96 pixels per inch, they can't display a 300 dpi image in actual size, when viewed at 100%.
- The image will look much larger than the print version because the pixels on the screen take up more space than the dots on the paper.
Applications:
| Resolution | Types of picture is good for |
| 72 dpi |
Any picture that will be shown on a computer screen. Web pictures should have this resolution or they will be too big
|
| 150 dpi |
Good for basic print jobs in either B&W or color. Drawings and posters work great at this resolution.
|
| 300 dpi |
For high quality (Photographic and artistic) printouts on a black and white printer.
|
| 600 dpi |
For high quality printouts on the SCIC color printer. A higher resolution is not recommended (It takes long enough to scan and load 600 dpi pictures).
|
- Increase the quality of image if more dots in inch.
- Increase in the size of the halftone dots during printing.
Disadvantages:
- Lower spatial resolution, which can make text and lines look some what wrong.
- Lower output speed.
- A wasteful dye-film roll cartridge system
My notes images:
