Increase the quality and resolution of an image.

How can altering resolution increase image quality?

In digital photography, image resolution ties directly to image quality. Key to this are ‘pixels’.

Pixels are the building blocks of digital photos and other raster image files. Each of these tiny blocks contains detail and information for your image. Generally speaking, higher pixels density increases the resolution of an image.

Digital image resolution is normally measured as PPI – or pixels per inch. Hence, a greater PPI value can bring about a more quality image.

• Depending on where and how you’re using your image, you might opt for a different resolution.
• For example, as digital images take longer to load online, the standard is generally held to be 72 PPI.
  
• If you were displaying a digital image for a billboard ad, however, you’d likely go far higher than this.
  
• On the other hand, you might choose a lower resolution if you were making a simple thumbnail image, or some charmingly lo-fi pixel art.

Want to know more about PPI - pixels per inch? Check out our complete guide.

Can you increase the image quality of a low-resolution photo?

Picture a familiar scene from the movies: a detective asks a tech-savvy police staffer to “enhance” a blurry image on a computer, until it becomes clear enough to make out a key piece of the puzzle.

But can you really make an image higher resolution in real life? Actually, the answer is yes — though it sometimes takes more than a few clicks.

The only way to resize a smaller photo into a larger, high-resolution image without highlighting poor image quality, is to take a new photograph or re-scan your image at a higher resolution.

You can increase the resolution of a digital image file, but you will lose image quality by doing so. Why? Because the number of pixels on your photo is generally fixed by your camera. While you can increase image size (and even add pixels) using editing software, you’ll often find the image becomes grainier.  

However, there are some measures you can take in Adobe Photoshop to help you increase resolution while upholding visual quality.

How resampling and interpolation can change the resolution of an image.

Resampling images in Photoshop means changing their resolutions by adding or subtracting pixels.

When looking to make an image higher resolution, there are two main resampling methods:

• Downsampling decreases the number of pixels in your image. This removes data from your image.
• Upsampling increases the number of pixels in your image. This adds data to the image.

When you increase the number of pixels in an image without adjusting the dimensions, you are adding more pixels into the same amount of space and increasing the resolution (or amount of detail) held within each inch.

However, upsampling doesn’t increase the detail or depth of an image. Instead, it’s generally used to smooth over pixelation of very low-res images. If you’re looking to get a great quality image with light, shade, depth and detail, you’ll need a high megapixel camera first.

Choosing the best interpolation method when upsampling.

Removing data is preferable to adding it, since Photoshop will have to guess at how any newly added pixels should look. As a result, upsampling doesn’t often result in a better-quality image.

The interpolation method can help. This is how Photoshop chooses the colour values of new pixels. 

Choosing the correct interpolation method can help avoid unwanted pixelation:

• Automatic. Photoshop chooses the resampling method based on the image type.
• Preserve Details. An advanced upsampling algorithm with a Noise Reduction slider.
• Nearest Neighbour. Best for illustrations with hard edges and no anti-aliasing.
• Bilinear. Adds pixels by averaging the colour values of surrounding pixels.
• Bicubic. Produces smoother tonal gradations than Nearest Neighbour or Bilinear.
• Bicubic Smoother. Good for enlarging images. Designed to produce smoother results.
• Bicubic Sharper. Good for reducing the size of an image.

When you’re done resampling, applying the Unsharp Mask filter can help enhance image quality. 

How to increase resolution of an image in Photoshop.

There are plenty of reasons why you might want to convert an image to high resolution.

You may be looking to enhance a lower-resolution photo to print it. For example, a high-resolution TIFF file is a better printing format than a low-resolution JPEG.

If you are open to different image sizes, first try changing the dimensions and resolution of your photo without resampling it. For example, you could potentially crop your image and focus on an individual detail to get a better-quality result.

This means working with what you have, not adding new data to the original image. You can always resample as necessary after you’ve tried adjusting dimensions and resolution  separately.

In this way, Photoshop can act as something of an image resolution enhancer.

Change print dimensions without adjusting pixel dimensions.

See if you can increase image quality for print by adjusting only the dimension or resolution, without changing pixel count.

Photoshop will automatically change the other value for you, keeping the aspect ratio and amount of pixels the same.

Follow these steps.

1. Open your image in Photoshop.
2. Choose Image › Image Size.
3. Deselect Resample. This will automatically lock the current ratio of Width and Height.
4. To adjust Resolution, add new values. Photoshop will automatically change the Document Size to match.
5. To adjust Document Size, add new values under Height and Width. Photoshop will automatically change the resolution to match.

Change resolution by adjusting pixel dimensions.

If you have specific needs for the dimensions or size of your image — like a poster at a certain print size — check the box for Resample.

This allows you to adjust the print size and change the image resolution independently, which changes the number of pixels in the image. Get started with these steps.

1. Open your image in Photoshop.
2. Choose Image › Image Size.
3. To maintain the current ratio of Width to Height, be sure the chain icon linking these properties is activated.
4. Under Dimensions, enter values for Width and Height. The new file size for the image appears at the top of the Image Size dialog box, with the old file size in parentheses.
5. Select Resample and choose an interpolation method.
6. If your image has layers with styles applied to them, select Scale Styles under the gear icon to scale the effects. (This option is available only if you selected Constrain Proportions.)
7. When you finish selecting options, click OK to resample your resized image.

Enhance and sharpen images without resampling.

There are ways to make your image look clearer and appear more high-resolution without actually adding pixels or changing the dimensions. 

• Try enhancing the overall look of an image in Photoshop using the Camera Raw filter.
• …OR sharpening the details in a photo, using the sliders in the editing panel in Adobe Photoshop Lightroom.
  

Attempting these methods can help get the highest quality you can out of the digital information you have in your image.

Lightroom, Photoshop and other software: which is best to improve photo quality?

Adobe Lightroom and Photoshop are both industry standards for image editing. But you might find other Adobe tools suit you better.

Here are a few options for changing the resolution of your image, and other useful digital photography tasks.

• Lightroom — Powerful editing capabilities meet organisational tools. The perfect choice for pro photographers who need to both improve photo quality and project manage at the same time.
• Photoshop — Use resolution changers and retouch all sorts of images. Build in stunning effects to photos, art and other media.
• Photoshop Express — Change the resolution of your images from your smartphone.
• Lightroom Classic — The editing and project management of Lightroom, optimised for desktop.

Lightroom vs Photoshop: which is best for you?

Increase image resolution: FAQs.

How can I make a picture higher resolution for free?

You can resize, retouch and increase the resolution of your images for free using Adobe Express. Use our user-friendly platform to resize images in a flash. You can also access Adobe Photoshop, Lightroom and more using a free trial.

How can I change the resolution of a JPEG?

You can change the resolution of a JPEG image using a range of Adobe products, including Photoshop and Lightroom. Simply go to File>Export, then toggle your image resolution higher / lower – or simply click ‘optimise for web’.

How do I improve image quality in Photoshop 2020?

You can enhance image quality using Adobe Photoshop in a number of ways. Resample and interpolate to increase pixel levels, or change print dimensions to strike the right balance without altering the original image. You can also mix up contrast, vibrancy and saturation to improve colour.

Discover more about image resolution, editing and photography.

• Image resolution explained
• What is high image resolution?
• How to optimise images
• Lossy compression explained
• Lossless compression explained
• Lossy v lossless compression explained