How to create alpha mask from an image in Photoshop CS/8
I have a monochrome image, and would like to replace the colour with a gradient.
I assume the best way to do this would be to create a background layer with the gradient, and then apply the monochrome image as a mask. However, I can't for the life of me get this to work. If I copy the image, and then try to paste it into a mask layer, it just creates a new normal layer and pastes it there.
How to accomplish this?
I don't have version 8 anymore, but try this.
- Select All and copy the image from the layer you want to use as a grayscale mask.
- Switch to the channels tab of the layers panel.
- Add a new channel. Paste your image data in that new channel.
- Click the button on the bottom of that panel labeled "Load channel as Selection" â€” you will get a marquee selection of the alpha channel.
- Switch back to the layers panel, click on the layer you wish to apply a mask to and click the button at the bottom of that panel "Add Layer Mask".
That should be all you need. There's probably an easier way, but I can't think of it right now.
Method 1 (Adds a simple gradient):
Convert your monochrome image to RGB (Image > Mode > RGB).
Double-click the background layer to convert it to a regular layer.
Add a new layer below the image (Ctrl/Cmd Click on the new layer icon).
Fill that layer with the color gradient.
Change the blend mode of the image layer to "Luminosity."
Method 2 (Recolorizes the image):
Convert your monochrome image to RGB mode as above.
Add a Gradient Map adjustment layer.