You can change the size or resolution of a digital picture by changing:
The number of pixels. The resolution, or sharpness, of a picture is determined by the number of pixels it has. For example, more pixels improves the resolution of a picture, which allows you to make a larger print without reducing visual quality. Keep in mind, however, that the more pixels a picture has, the larger its file size will be.
The file size. The amount of space a picture takes up on your computer and how long it takes to e‑mail is determined by the picture's file size. Though more pixels often means a larger file size, the picture's file type (JPEG or TIFF, for example) usually has more to do with file size. A picture saved using TIFF will be much larger than the same picture saved using JPEG. This is because JPEG pictures can be compressed, which makes the file smaller at the cost of slightly lower visual quality. If the picture is not already a JPEG, you can usually save a significant amount of space by saving the file as a JPEG, and then deleting the original TIFF version from your computer.
To reduce the number of pixels so that a picture can be sent to another person in an e‑mail message, see Send pictures or videos in e‑mail.
There are many common picture editing programs available that include a resize feature to change the number of pixels.
To reduce the file size so a picture can be sent to another person in an e‑mail message, see Send pictures or videos in e‑mail.
Many common picture editing programs allow you to change the quality level of a JPEG picture when it is saved. When using the program, look in the program's Save As dialog box for an option to change the compression or quality level. The lower the quality (or higher the compression), the smaller the file will be when it is saved.