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[Solved] Can export resolution be changed?

Posted: Wed Mar 27, 2024 11:06 pm
by ozzie_traveller
G'day all

Issue-1
Export resolution is preset as 96dpi ... I need hi-res 300dpi sometimes 600dpi, yet the image is pixellated badly upon opening -- there's no difference between 96dpi and 300dpi when I do so.
Q- is there a solution?

Issue-2
The text relating to file-size chosen seems back-to-front ... 9 is largest file size =and= slowest loading -- or so it seems to me
Q- have I got it back-to-front?

Many thanks, Phil
O-O+Grafic JPG screen.jpg
O-O+Grafic JPG screen.jpg (24.09 KiB) Viewed 9684 times

Re: Exporting options - can it be changed?

Posted: Wed Mar 27, 2024 11:29 pm
by Hagar Delest
You are talking about the PNG export, it is not a good format for a picture, especially if it comes from a jpg.
All depends on your source picture. If the resolution is 300dpi for example, exporting as 600dpi won't improve the quality.
For PNG, I guess that the encoding is more complex with 9 because it optimizes the sorting of the pixels to reduce the file size. Thus is will take more time to decode the "map".
Usually, for a jpg, the setting is the quality (not the compression), thus the lower the value, the smallest the file size, but the poorest the quality.

Re: Exporting options - can it be changed?

Posted: Thu Mar 28, 2024 12:26 am
by ozzie_traveller
G'day Hagar

Thx for the prompt response

My original is a 1200dpi (4000px wide) master image of which I am cropping smaller chunks for a report
I am playing / experimenting with export into PNG or BMP or JPG formats and they all seem to end up much the same
I will continue playing !!

2) my Q above is "are the words 'smallest' and 'largest' in the incorrect places? should they be reversed?

Thanks, Phil

Re: Exporting options - can it be changed?

Posted: Thu Mar 28, 2024 12:50 am
by robleyd
2) my Q above is "are the words 'smallest' and 'largest' in the incorrect places? should they be reversed?
No - the numbers refer to the amount of compression of the image, from 0, none to 9, maximum amount. Obviously the more the file is compressed, the smaller it will be.

Re: Exporting options - can it be changed?

Posted: Thu Mar 28, 2024 12:54 am
by Hagar Delest
So it all depends on the size of the cropped image. If too much cropped, of course the result will end up showing pixellisation.

For your second question, that's what I told: 0 is low compression, thus biggest file size than with the highest compression (9).

Re: Exporting options - can it be changed?

Posted: Thu Mar 28, 2024 5:27 pm
by MrProgrammer
ozzie_traveller wrote: Thu Mar 28, 2024 12:26 am are the words 'smallest' and 'largest' in the incorrect places? should they be reversed?
The descriptions are correct.
0 is the biggest file size and fastest loading because no compression is used when the file is written, hence no decompression (which takes extra time) is needed during open. 9 is the smallest file size and slowest loading because the most complex compression algorithm is used to create the smallest file, hence maximally time-consuming decompression is needed during open. In practice, however, modern hardware is quite fast and you are unlikely to see much difference in speed unless the file is really enormous. Given that storage capacities and broadband speeds are far larger than they were years ago I think there is not much to be gained now, in most situations, with any of the high compression factors.

ozzie_traveller wrote: Thu Mar 28, 2024 12:26 am My original is a 1200dpi (4000px wide) master image of which I am cropping smaller chunks for a report
You should be using a Raster graphics editor for that task. Draw is a Vector graphics editor and not an appropriate tool for you. Use of the wrong tool is the cause of your difficulty. This topic is a bit like asking for help installing screws with a hammer. The best advice is to use a screwdriver.
Comparison of raster graphics editors

If this solved your problem please go to your first post use the Edit button and add [Solved] to the start of the Subject field. Select the green checkmark icon at the same time.

Re: Exporting options - can it be changed?

Posted: Thu Mar 28, 2024 10:59 pm
by ozzie_traveller
Thank you both for your answers and assistance.

In this instance I am working with original photo images and cropping 'windows' for insertion into a document--rather than graphics originated in Draw
I have experimented with export as JPG and seen the different export screen, so now realise that I had the instructions back to front!

I will do some homework re the links above

Thanks again, Phil