Explain about image size and its resolution?

Explain about image size and its resolution?

Managing file size is important when working with digital images, if you don‘t keep track of your file sizes you may end up with very large images, and this will undoubtedly cause problems somewhere down the line, large files eat up disk space quickly, crash printers, slow down web browsers, etc. so it is better to set a correct image size based on our requirement, it is possible to keep our file sizes as low in Photoshop.

To check physical dimensions of an image, then go to image‘ menu and select image size‘, it will display the following dialog box:

  

Notice that there are two sections to this window.

ü The upper section allows you to adjust the number of pixels used for the image. This is how much data is available in the image. Imagine an image of a face with only 10 pixels of information per row and column, you probably would be able to tell that it is a face, but it would be unrecognizable.

ü The lower section of this window allows you to adjust the print size. This is how you adjust the physical size of the image. You can print out the 10X10 image. Changing the print size does not adjust the amount of information, and therefore the size of the file.

ü The resolution is the pixels/inch. This ratio relates image size to print size. 72dpi‘ is the default resolution used for online graphics, 150-300 dpi is used for printing.