acp3_2 now has an option called Image Upload Auto Downscale which when enabled will automatically downscale images selected by the user before they get uploaded to the cloud. For images with large dimensions, the result of this will be faster uploads.

The specific use case for auto downscaling is kiosks in shops which might have poor internet connections and need to minimize the amount of time customers have to wait. However it does have a lot of general benefit and might be enabled as default in the future.

There are several options for fine tuning behaviour:

Option Values Default Description
Auto Downscale Width 1 → 9999 1500 The maximum width for downscaling
Auto Downscale Height 1 → 9999 1500 The maximum height for downscaling
Auto Downscale Quality 0.01 → 1.00 0.95 The quality of the resulting image (only for JPGs)
Auto Downscale Format image/jpeg, image/png or auto image/jpeg The format to convert the image to.

When downscaling the image, its aspect ratio will never be broken.

The default size of 1500x1500 pixels means that the image would be suitable for image areas up to a maximum of 127mm x 127mm at 300 DPI or 254mm x 254mm at 150DPI.

Initial testing with default settings has shown that a 7.7MiB JPEG at 4928x3264 pixels is reduced to 0.27MiB at 1500x1500 and 95% quality with no noticeable difference in final artwork quality for a 87mm x 136mm image area.

image/jpeg will generally give much smaller files than image/png but may result in a noticeable loss in image quality. auto can be used to preserve the format of the user’s image.


  • Auto Downscale is only available for PNG and JPG images. Any other image formats will bypass the downscaling.
  • Artwork quality will be negatively affected if the maximum image size is smaller than the print size of the image area.
  • For large images, performance on low power mobile devices may be an issue.