Trouble with image export

I’m getting less than ideal results when exporting images.
My page is 6" wide X 12" tall. I am exporting to PNG at 600 DPI.

The resulting file is 96 DPI, 36" wide X 72" tall. Note that this is almost inversely proportionate, but not quite. The DPI would need to be 100 for this to be exact. When I change the DPI to 600 in my photo editor, I get an image that is only 5.76" wide.

If I try the same thing in MuseScore, I get an image that is exactly 600 DPI and 6" wide.

Am I doing something wrong?

Thank you,

For a bitmap image, what matters is the size of the image in pixels, not the number of “DPI” (which isn’t even stored in the file, for some bitmap formats).

Presumably you are trying to create an image with 3600 x 7200 pixels. If Dorico is making some assumptions that include “96 DPI” (which is the standard resolution for “normal” computer monitors) when calculating the size in pixels, the workround would be to export your image as size 6.25" x 12.5" at 600 DPI, or alternatively 6" x 12" at 625 DPI.

I’m “just a user” so I don’t have any information on why this happened in Dorico.

Thanks, Rob. I can get around this as you suggested, but it would be so much easier if the export feature worked as expected. When I process these images the software I use requires an additional step to scale the resolution to 600. This adds up when there are hundreds of images.

Really, you should be specifying the size at which the image should be included in the destination document or web page, or the size it should be printed, rather than “scaling the DPI resolution” for each image to make it the correct size.

If your software can set up some sort of page layout template that uses all the images, maybe you only need to define the output size (in inches) once, however many images there are.

Clearly you want to match the number of pixels per inch in the final size to the resolution of your printer or other output device, but that only depends on generating the images with the correct number of pixels, not on editing the “DPI”. Just let the software scale a 3600 x 7200 pixel image to fit in a 6" x 12" box and you will get “600 DPI” automatically.

I would prefer not to mess with the DPI at all, but the software that I’m loading the images into pays attention to this. The bigger problem is that the exported image is 4% smaller that it should be even once the DPI is factored out.