Do you want to print a photo but the resolution is too low?
Photoshop can increase the resolution of an image. It does this by calculating and adding extra pixels.
I’ll show you how to increase the resolution of an image and what to look out for in five easy steps.
What Is Resolution?
Resolution is the number of pixels in dimensions of height and width.
For example, the manual of my camera says that the resolution is 8256 x 6192 (W x H) pixels. That means the total amount of pixels is 8256 x 6192 = 51,121,152.
Divide that number by one million. The result is the amount of megapixels the camera has. In my case that’s 51MP and it also describes the resolution.
More pixels in an image mean higher resolution. This is because pixel information is denser.
Higher resolution gives you more detail and more detail means you can print larger. The result will be smooth, continuous tones and colour transitions.
How to Increase the Resolution of an Image
You can easily increase the resolution of an image in Photoshop but there are limits.
It all depends on the amount of detail in the image and the purpose of it. It takes some practice and trial and error to know how far you can go.
Step 1: Image Size
Go to Image > Image Size… to open the Image Size window.
You can also use the shortcut Opt + Cmd + I (Alt + I for Windows).
Step 2: Increase Image Size
There are a few options to increase the resolution of your image. First, you can pick one of the presets based on standard paper and print sizes.
Use the ‘Fit To’ drop down menu to pick a preset.
Usually, it’s better to set the amount yourself. If doing so, make sure to select the ‘Do not constrain aspect ratio’ icon.
Now, if you increase the Width, the Height will increase automatically. Photoshop keeps the aspect ratio of the original image.
Type the amount of pixels you want in the Height or Width box.
Step 3: Resolution
This box sets the number of pixels per inch (ppi). Everybody says this number has to be 300 to print the image but that’s not exactly true.
An image measuring 3000 x 2000 pixels set at 300 ppi will print exactly the same as 3000 x 2000 at 72 ppi.
The difference will only be visible on screen. The 72 ppi image will appear larger on a screen than the 300 ppi image.
So, you can just leave this number as it is.
Step 4: Pick a Resampling Mode
The resampling mode decides which algorithm Photoshop will use to add new pixels.
There are two good options for increasing the resolution: Preserve Details and Bicubic Smoother.
I find that Bicubic Smoother gets the best results. You can try both the see the difference.
Here’s a comparison of all the resampling modes.
Tick the Resample box and select a resample mode that works for you.
Step 5: Sharpen
It’s always a good idea to sharpen after you’ve increased the image resolution.
Go to Filter > Sharpen and select Unsharp Mask.
Drag the Amount slider to 100% and the Radius to 1.0. That’s a good setting to start with when enlarging an image.
You can add more or less sharpening if the result doesn’t look good.
Photoshop does a good job at increasing the resolution of an image but there are limits. The quality and size of your starting image will decide if you’ll get good results.
For example, an image with a resolution of 100 x 100 pixels can’t be resized to 3000 x 3000 pixels and look god. That’s just too much to ask.
It also depends on the purpose of the image. Do you need a high quality gallery print or a banner to hang against the wall?
An image for a banner doesn’t need a super high resolution to look good. Always ask the printer what the minimum resolution that he needs is.
Why not check out our posts on different photo file types or editing product photography in Photoshop next!