Start with what the application actually measures

An upload may specify width and height in pixels, while a printed photo is measured in millimetres or inches. A DPI or PPI setting describes a different part of the workflow. Do not assume that changing that number is the solution to a failed upload when the portal asks for a particular pixel size.

Some instructions do specify scanning resolution. The US visa digital-image guidance, for example, gives a 300-pixels-per-inch requirement for scanning an existing 2 × 2 inch photograph. That specific instruction should not be turned into a universal rule for every digital passport photo.

Use a simple calculation for print

Divide the number of pixels across the image by the intended width in inches. A 600-pixel-wide image printed two inches wide has 300 pixels per inch. Print the same image four inches wide and it has 150 pixels per inch. The file contains the same image information in both cases.

PPI refers to image pixels per inch. Printer specifications may use DPI for physical ink or toner dots. Those dots are not interchangeable with image pixels, even though software and everyday instructions sometimes use the terms loosely. Follow the requested image and print dimensions first.

Changing the label and resampling are different

A resolution label can tell software how large to print an image without adding pixels. Resampling changes the pixel dimensions themselves. If an editor offers both options, check which one is active before saving so that an attempt to change print size does not accidentally make the file smaller.

Increasing the pixel count of a tiny portrait does not recover the detail of a high-resolution original. The image may meet a numerical minimum while still looking soft. Keep the full camera file and prepare the required output from that source whenever possible.

Verify the result in the form it will be submitted

For an upload, inspect the saved pixel dimensions, file type and file size. For a print, measure the actual paper photograph and inspect the face for visible softness or printer artifacts. A correct resolution tag does not compensate for a wrong crop or poor capture.

If an upload error mentions resolution, copy its exact wording into your notes. It may mean pixel dimensions rather than a DPI tag. Check that requirement before repeatedly exporting the image at different settings.

Sources and further reading

US Department of State · Digital visa image requirements ↗Apple Support · Crop, resize or rotate an image in Preview ↗

Requirements can change. Check the official instructions for your application before submitting.

Merodim is an independent photo-preparation service, not a government agency. Find your document →