I will try to describe you regarding how to use masking techniques in photoshop.
Make a duplicate layer of the image. This way the original is preserved on the background and we are working on a duplicated layer. Choose Select>Color Range from the Menu. When the Color Range Dialog box open, choose the Left Eye Dropper tool and click on the background color in the image window (pink). You will see the selected color turn white in the dialog box. More the Fuzziness slider until the image is mostly black and the background is a clean as you can get it. Tip: To add a color to the selection click on the eyedropper tool with the plus sign and click in the image. Click ok
With the selection active, switch to the Channels palette. Click the save selection as channel button, it’s the second one to the left on the bottom of the channels palette. A new alpha channel will now be visible. Press “Ctrl/Cmd+D” to Deselect and click on Alpha 1 in the channels palette. The main window will now turn black and white. The advantage of using a channel is the ability to fine tune the selection without effecting the original image. Black represents the areas that we want to keep and white, the areas to be discarded.
Step : 3
Notice that there are areas of gray, these would be semi-transparent and need to become solid black and white (except for areas that should be semi transparent such as soft edges). There are tiny dots also visible, there will make for a very messy selection. Here is a quick solution that I have come up with: Click Image>Adjustments>Levels..
In the levels Dialog box, click the black point slider on the left and drag it to the right until the gray areas have become a solid black, Slide the White point slider to the left until the whites are nice and clean and the grainy effect has gone. Click ok to apply.
Time to fine tune the mask. Choose a black brush and make the edge hard. Paint over all the areas that belong in the object to mask out. Use a larger brush for large areas and a smaller brush for finer detail such as around the feathers. Use a white paint color to paint out the areas that should be removed.
Sometimes it can be hard to guess which part of the image belongs in the foreground and a peek at the original image is needed. Click on eye icon to the left of RGB at the top of the Channels palette (Fig 5). The original photo is now visible and the mask appears as a reddish color. Click the eye icon to go back to the mask view. The mask can also be hidden by toggling the eye (visibility icon). Keep going until you have a clean mask.
Hold Cmd(Ctrl PC) and click on the Alpha 1 thumbnail. You will now see an active selection. Click on RGB to see the color image. Open the layers palette. Select the working layer and press the Delete key (Backspace on Windows). The masked area of the backround will now be removed to reveal a nice clean masking effect. At this point In am only worried about removing the pink background on the left.
If there are areas that still need to be removes such as on the right side of this image, repeat the proceeding steps. Because each image is unique, some will need several passes and some can be done in a single pass. As you can see, this technique is very effective and the image can be dropped onto any background. Look at the top left of the image to see how precise the cut out is on the detailed feathers.
we’re going to look at one of the most essential features in all of Photoshop – layer masks.