RBEU wrote:
GIMP Version: 2.8.14
...The Gimp file I have created is about 8MB. However, when I save the picture as a JPEG with quality of 100, the max I can get is 4MB.... To print the photo onto a canvas I need at least 7MB. Does anyone know what I can do about this?
To me it reads that the collage was started with a size too small.
Time to look at the different formats for images and the filesize produced. Starting out with straight-from-camera jpeg image about 5 MB (4800 x 3300 pix)
Gimp 2.8 images are compressed to a certain extent (RLE) and can be further compressed xcf.gz / xcf.bz2
What is the difference? Efficiency, but time to open an image can be longer.
Lossless formats
plain-gimp.xcf 46 MB
compressed-gimp.xcf.gz 34 MB
more-compressed-gimp.xcf.bz2 28 MB
default-png.png 21 MB
When it comes jpeg, compression is very efficient but it is lossy. Quality is not linear. 100 to 90, big saving in file size without much visible difference in quality. 70 and less, not much change in file size, big loss in quality.
lossy
100jpg.jpg 9.4 MB
95jpg.jpg 4.8 MB
85jpg.jpg 2.8 MB
All that means, file size is no real guide.
When it comes to printing, depends on the size to be printed, photo 6"x4" or A4 or printed as a poster. That is where the image size in pixels comes in