.:DPI, Pixel, and Resolution 411:.

Have you wondered how a image is represented and how all the lingo or terminology all fits together? The folowing will shed light onto the 'numbers' and explain the relationships between the concepts.
Physical images or print is explained in inch's, for example a 4x7 photo. However, on a digital device such as a camera or monitor they are represented as pixels.
Pixels are the smallest basic units that compose a digital image. The measurement 'Pixel' is an abgreviation from "picture element". An image is composed of many tiny pixels together, and to the naked eye it makes up of the image you see. Pixels do not have a fixed sie or measurement in inches, so the size of one pixel depends on the quantity of pixels that compose an image of a fixed size.
A monitor screen is is measured in pixels as a resoltuion size - then further configured to dpi (dots/points per inch) setting. The dpi setting tells how many pixels per square inch to display within the given resolution (I.E. 1024x768 is a common size).

Scanning to make a perfect quality image for your videos is very important. And the incorrect image dpi can hinder photo correction and degrade your video's overall quality. One bad image can spoil the entire montage.
The higher the scanning resolution, the more pixels the scanned image will have. For standard size photographs, scanning at 300 dpi will allow you to print later at 300 dpi at original size. Scanning at 150 dpi or suitable for viewing on a computer screen, posting to a website, or printing at lower quality.
For slides and negatives, which are smaller in size, larger scanning resolutions are needed. A 35 mm color negative is 1.42 inches wide x 0.95 inches high. Scanned at 1500 dpi will create a 2130 x 1425 pixels image, which printed at 300 dpi will result in a 7.1 inches x 4.75 inches print.
In digital terms, each pixel is simply a piece of information regarding the specific color and brightness of that particular dot. For each pixel, this information is contained in three bytes representing each one these the particular shade of Red, Green, and Blue (RGB) that combined together make up the specific color and brightness of that pixel.

In short...

If we scan an image at 150 dpi then scan the same image at 600 dpi the detail variation is dramatic!
As shown below you can see the loss of quality which is called "pixelation", where you can see the individual pixels when zoomed in close.
This pixelation is what destroys the look and quality of your image...

Click to view the upclose large version.

High quality scans are very important.