How do I use photoshop to filter a layer?

This is a follow up to a previously asked question. How to remove a square background from a round logo. I have Photoshop CS4 available, but have very little experience with it. All I have managed to do so far is make the background checkered.How do I use photoshop to filter a layer?
Uh, if the background is solid colour, you can use Select -%26gt; Colour and select the colour, otherwise you're going to have to render it by zooming in to like 400-500% and using the pen tool to cut it out, cos you can do individual clicks with the pen tool, then right click to turn it into a selection.





It's complicated, takes time to master the Photoshop series.How do I use photoshop to filter a layer?
A checkered background means transparent. Photoshop uses the checkers so that the user (you) know that the background is transparent.





Once all you see is the round logo and everything else (the square and all) is 'checkered' you are done.





Now, if you want to save it like that so that the background stays transparent, you can 'save as' and save the file as a PNG file format - when used in web development, the PNG format maintaing its transparency.





If you want to add a different background color, simply add a layer UNDER the round logo, make sure that layer is selected, and fill it up with a color.





once done, you can 'save as' a JPG or any other format that works for you.