Open an image in Photoshop. Choose Image > Image Size.
Do any of the following:
- To change image size, enter values for Width and Height. To maintain the original ratio of width and height, select the Constrain Proportions option. Deselect this option to adjust the width or height independently.
- To change the Resolution, enter a new value.
- To change the image size or resolution while allowing the total number of pixels to adjust proportionately, make sure that you select Resample.To change the image size or resolution without changing the total number of pixels, deselect Resample.
Click OK. Photoshop resizes the image based on the values you entered.