Certain aspects of an image need to be brought out, and this can be very difficult to do especially when there is a lot going on in the picture already. There are quite a few tools available to help you change and modify colour settings, but that doesn’t necessarily mean it will help an element of an image stand out.
Curves edit input and output with the image and this can help draw attention to the image you want to grab attention. Making the image stand out a little more will require selecting the image, either by using something like the polygonal lasso tool, colour range selector or for the lazier web designers, the magic wand. Using the curve tool is more by eye as opposed to an exact “how to” guide. If you want to make an image stand out, create a curve which is closer to the top left hand corner. This will take some playing around with to get the levels just right but the time you can spend on this will range depending on how perfect you would like it.
If you really want your image to stand out as much as possible, you’re going to have to reduce the amount of attention your background receives. So again a very similar process like before, make sure all of the background is selected and the image that you are trying to draw focus to is deselected. The curve you will need to create should point close to the bottom left. Again this will take some playing around with to get just right but it depends on the kind of effect you are going for with the curves.
When using Photoshop as a tool for web design, some objects may need to be brought out to help draw more attention to it and make it as a main focus. This can be very helpful with things like products and people. The situation in which curves will be used will definitely change and the approach you take as a web designer will change too.