12-03-2019, 09:30 AM
Gimp will not change the size in pixels when you change the print size. Print size and print definition are just metadata, they can be changed at will. Changing the size in pixels is somewhat final (once you have scaled down, scaling up again will give you a blurry image).
Which doesn't mean that in your case the size in pixels could be much bigger than what you really need. At 300PPI (~120 pixels/cm) your current image is 177x177cm. If you intend to print is at a much smaller size, for instance 20x20cm (7.87 inches) then at 300PPI you only need an image which is 300*7.87=2362pixels. So you can use Image>Scale image to downscale your image. And even if you need a physically large image, the larger the image, the further away people are, so you can reduce the resolution (billboards are a 10PPI or less...). In practice you rarely need to be bigger than 12Mpix, so you could downscale your image to 4000x4000.
Which doesn't mean that in your case the size in pixels could be much bigger than what you really need. At 300PPI (~120 pixels/cm) your current image is 177x177cm. If you intend to print is at a much smaller size, for instance 20x20cm (7.87 inches) then at 300PPI you only need an image which is 300*7.87=2362pixels. So you can use Image>Scale image to downscale your image. And even if you need a physically large image, the larger the image, the further away people are, so you can reduce the resolution (billboards are a 10PPI or less...). In practice you rarely need to be bigger than 12Mpix, so you could downscale your image to 4000x4000.