to copy the picture from a website into database automatically

How can i compare the Logo of a website to the开发者_运维技巧 logo available in my database just by entering the url to the particular explorer?do i need any plugins or it is simple enough?

It would be simple enough to fetch the file and compare into a byte level, but this will only match completelly identical files.

You'll have to write some code. Write a java program to fetch the URL from the web site and to fetch the image from the database (perhaps using the URL as the lookup key) and compare each logo's checksums.