Fairly straight-forward image to work with.
Realize that if you want high-quality image you can scale to any size, you’ll need a vector version of the logo. Using that particular PNG is never going to result in a high quality image. At best you can get an image the same size or smaller without the background. Anything else would require recreating from scratch in a better format.
To get rid of the background in that particular image it just takes a few steps with Photoshop.
- Open the image
- Look at the Channels Panel (Window > Channels) and find a channel with a good contrast ratio. In this case, the green channel.
- Duplicate the (green) channel so you have a new channel “Green copy”.
- With “Green copy” highlighted in the Channels Panel, choose
Image > Adjustments > Levels. Click the
Autobutton, then move the left slider (white) to the right until it is inside the little black peaks you see. Then move the right slider (black) to the left so it is inside the little black peaks on the right. and click
- Hold down the Command/Ctrl key on the keyboard and click the thumbnail image for “Green copy” in the channels panel to load it as a selection. You’ll see the “marching ants”.
- Highlight the Layer in the Layers Panel.
- Hold down the Option/Alt key and click the
New Layer Maskbutton on the bottom of the Layers Panel.
That should provide an image with the background masked out. You can save the image as a PNG to retain the transparency, or add new layers below the image layer with any color you wish.
You can double-click the Layer mask in the Layers Panel to further refine the things as needed. In some cases there may still be a slight color matte around the image. So refining the mask is necessary.