force image to download not to display in browser

[HaRoOn]

How can I force an image to be downloaded but not displayed in the
browser window? please give me some solution in either javascript or
php.

 

[scripts.contact]

How can I force an image to be downloaded but not displayed in the
browser window? please give me some solution in either javascript or
php.

new Image().src="img src"

or in html-
<img src="img src" style="visibility:hidden"> <--- dont use
display:none