How do you create an alpha channel from a selection in Photoshop?

1 What is an alpha channel?

An alpha channel is a special type of layer that stores information about the opacity of each pixel in an image. It is represented by a grayscale image, where white pixels are fully opaque, black pixels are fully transparent, and gray pixels are partially transparent. You can think of an alpha channel as a mask that reveals or hides parts of an image or a layer.

2 How to make a selection in Photoshop?

Before you can create an alpha channel from a selection, you need to make a selection first. There are many tools and techniques to make a selection in Photoshop, depending on the shape and complexity of the object you want to select. Some of the most common tools are the Lasso Tool, the Magic Wand Tool, the Quick Selection Tool, and the Pen Tool. You can also use the Select and Mask workspace to refine your selection and adjust the edges, feathering, and output settings.

3 How to save a selection as an alpha channel?

Once you have made a selection in Photoshop, you can save it as an alpha channel by navigating to the Channels panel, usually next to the Layers panel. Click on the Save selection as channel button at the bottom of the panel to create a new channel named Alpha 1 which will display your selection as a grayscale image. To customize your channel, double-click on Alpha 1 and give it a descriptive name, such as Object Alpha, and select a color and opacity for it. Finally, click OK to save your changes.

4 How to load an alpha channel as a selection?

If you want to load an alpha channel as a selection, you can do so by using the Channels panel and holding down the Ctrl (Windows) or Command (Mac) key and clicking on the alpha channel thumbnail. Alternatively, you can go to the Select menu and choose Load Selection. In the dialog box that appears, select the alpha channel name from the Channel dropdown menu and click OK.

5 How to use an alpha channel for compositing?

Alpha channels can be used for compositing in various ways. For instance, an alpha channel can be loaded as a selection to isolate an object from its background and place it on a different image or layer. Additionally, the alpha channel can be used to mask a background or layer, creating a transparent effect. Furthermore, it can be used to blend two or more images or layers together and create a composite image by applying a layer mask, clipping mask, or adjustment layer. Lastly, opacity, color, contrast, and other properties of the images or layers can be modified to achieve the desired result.

6 How to edit an alpha channel in Photoshop?

If you want to edit an alpha channel in Photoshop, you can utilize the painting, editing, or selection tools on it. Additionally, you can use filters, adjustments, and transformations to alter its shape and tone. To view an alpha channel, go to the Channels panel and click on the eye icon next to the channel name. This will show the channel as a grayscale image on your document. You can also press Alt (Windows) or Option (Mac) and click on the channel thumbnail to see it in full screen mode. To preview how an alpha channel affects your image or layer, go to the Channels panel and click on the RGB channel name. This will show your image or layer with the alpha channel applied as a transparency mask. You can also press Alt (Windows) or Option (Mac) and click on the eye icon next to the channel name to toggle between the channel view and the image view.