Image dimensions only become meaningful when they are compared with the size and crop of the final export. A source that is adequate for an ebook may not contain enough detail for a paperback, square audiobook, or heavily zoomed composition.
Calculate the pixels the format needs
Multiply the final printed inches by the required pixels per inch. A 6 × 9 inch front at 300 DPI needs 1,800 × 2,700 pixels before considering bleed. A complete wrap needs substantially more horizontal information because it includes the back and spine.
Judge the effective crop
If the editor uses only half the source width or zooms deeply into a face or object, the remaining pixels determine quality. The original file dimensions can look impressive while the selected crop falls below the production requirement.
Do not confuse upscaling with captured detail
Resampling can create more pixels and modern enhancement can reduce visible artifacts, but neither recreates the exact texture, edges, or facial detail that the source never contained. Treat an upscale as a reviewed derivative, not proof that the original met the specification.
Check every output shape
A portrait source may satisfy the ebook cover and fail the square audiobook crop. A wide scene may suit a full wrap but require enlargement for the front panel. Preflight each purchased format from the actual crop and keep the source version attached to the project.