Resolution: It's not just for new years anymore

[Mark321]

Hi,

Okay. I have this problem and I'm sure someone here has the solution. It's about exporting bitmaps (jpeg and png). You see, I need to be able to export high resolution images (300, 600 dpi) and I want to be able to make the pixel count what I want it to be in XDP. So far, I have only been able to control one or the other but not both (specific pixel count or necessary resolution for printing). If anyone can elucidate me, that would be great!

Confused and frustrated here,

Thanks in advance for your wealth of graphic "know-how".

Mark

[PhilM]

Hi Mark,

You could make some new units in the Units tab of the Options dialog. Click the "New Unit..." button and make a unit called "px300" (say) which is defined as 1 unit is 240 millipoints. Click again and make another unit called "px600" which is defined as 1 unit is 120 millipoints. Then make one of those new units the default page unit (in the Units tab) and the default ruler unit (in the Grid and Ruler tab).

Then you can see the sizes and positions of things in 300dpi or 600dpi pixels while you are constructing the document.

If you know the size of bitmap you are targeting, you could set the document page size to be measured in your new units and then set "area to save" to "page" when you export. This will ensure you get exactly the output size you want, no matter what you draw.

(You will still have to manually change the export dpi to 300 or 600 when you export.)

Phil

[handrawn]

Hi Phil

I think your unit definitions may be slightly out [but there again I may be misunderstanding] - I make it 230 [230.4] for 300dpi, and 115 [115.2] for 600 dpi; based on a millipoint being 1/72th of an inch

[PhilM]

There are 72000 millipoints per inch.

So the size of a pixel (or "dot") at 300 dots-per-inch is 72000/300 = 240 millipoints.

Unless I've missed something obvious...?

Phil

[digitalphaser]

...Click the "New Unit..." button and make a unit called "px300" (say) which is defined as 1 unit is 240 millipoints...

Good tip!
But it's interesting. If I import the image in Xara, I can choose the original or reduced version.
When I open an image in Xara, the resolution is changed to 96dpi, although the size is displayed correctly.



Why? In the settings I have not found an answer.

[handrawn]

@ Phil

that is pretty obvious to me too, now you point it out

ok I ran it through and it works ok at 240 - guess I was over thinking it, sorry

[handrawn]

@digitalphaser

when I re-imported my test export it showed at 300dpi in the gallery... and on the status line

[mwenz]

There are 72000 millipoints per inch.

So the size of a pixel (or "dot") at 300 dots-per-inch is 72000/300 = 240 millipoints.

Unless I've missed something obvious...?

Phil

Well, I suppose it depends on whether one is using Adobe's definition of a point or Didot points...

[digitalphaser]

Yes, I forgot. If I click "Save", the image is saved with the original resolution(300dpi). Wonders!
It does not much disturb, but it would be more clarity.

[digitalphaser]

@digitalphaser

when I re-imported my test export it showed at 300dpi in the gallery... and on the status line

It is not about import. Import functioning properly.
This happens when I open image as a photo document.