06-13-2022, 11:57 AM
(This post was last modified: 06-13-2022, 01:57 PM by rich2005.
Edit Reason: typos
)
If the jpeg from your phone camera is anything like mine then the compression setting is 95. You can check by using identify -verbose filename.jpg There is a compression value in the listing.
A bit about jpeg, it is a lossy format, even a 99 setting is compressed and lossy. The jpeg compression -> file size curve is not linear. Not much visible loss in quality down to about 80 but can be a good saving in file size Below 50 big drop off in quality, less saving in file size.
You can get an estimate of file size when exporting a jpeg. Enable the "Show preview in image window"
PNG is a lossless format. Smaller compression = larger file size. 9 is default and best compression. It can govern how fast a large image loads. Smaller (lower value) compression loads faster. No difference in the image.
There are other formats, TIFF for example, but you are starting with a jpeg, you might as well continue. You will not save much space by packing jpeg/png files to an archive, they are already well compressed but 7zip is a good choice.
A bit about jpeg, it is a lossy format, even a 99 setting is compressed and lossy. The jpeg compression -> file size curve is not linear. Not much visible loss in quality down to about 80 but can be a good saving in file size Below 50 big drop off in quality, less saving in file size.
You can get an estimate of file size when exporting a jpeg. Enable the "Show preview in image window"
PNG is a lossless format. Smaller compression = larger file size. 9 is default and best compression. It can govern how fast a large image loads. Smaller (lower value) compression loads faster. No difference in the image.
There are other formats, TIFF for example, but you are starting with a jpeg, you might as well continue. You will not save much space by packing jpeg/png files to an archive, they are already well compressed but 7zip is a good choice.