PS 18 - How to keep the original image size while reducing the canvas size

Reducing a larger document to smaller size will remove most of the pixels. But, how do reduce the document size without affecting the pixels?

For this tutorial i have opened a jpeg image. You can also use you're existing workfile.

The size for this image is 5184 x 3456.

(fig 1.0)

Right-click on the 'Background' layer and select 'Convert to Smart Object'. Even though the layer is locked, you can able to convert to smart object.

Convert to Smart object will work only on a partially locked layers and not on a fully locked layer. Fully locked layer can be applied on a new or any existing layer and not on a background layer. When you create a new document or when you open any image file, the background layer is always partially locked.

When converting your existing document to smart object, you need to remove all the 'full lock' on the layers, else you cannot able to select the 'Convert to Smart Object'

(fig 1.1)

Now the layer is converted to smart object, you can now change the canvas size, by going to Image and select 'Image Size'.

I'll reduce my document size to 50% from the Image Size window.

(fig 2.0)

Notice the document size in both smaller size document and also for the smart object.

(fig 3.0)