Exporting; no prob, just a question

[oyster]

I print Xara as bitmap from PhotoShop 5; my program, monitor and printer are profiled (ColorVision) to give pretty faithful prints from the monitor.

Trouble is, I get jaggies.

Xara only exports at 72dpi, tho I tell it to export PNG at 240, the resolution that suits my Epson 1160 printer. How do I get bitmaps that reflect the smooth, antialiased lines of which Xara is rightfully proud? And why ask me for a resolution change if I'm to get only 72 no matter what I say?
O.

[oyster]

I print Xara as bitmap from PhotoShop 5; my program, monitor and printer are profiled (ColorVision) to give pretty faithful prints from the monitor.

Trouble is, I get jaggies.

Xara only exports at 72dpi, tho I tell it to export PNG at 240, the resolution that suits my Epson 1160 printer. How do I get bitmaps that reflect the smooth, antialiased lines of which Xara is rightfully proud? And why ask me for a resolution change if I'm to get only 72 no matter what I say?
O.

[Wolfgang]

Oyster,

why are you exporting as PNG in the first place ?
If you use TIF instead, you should not have any troubles printing in your desired resolution ..

On the other hand, I just tried exporting a PNG from Xara, then imported it to PS6.

If you draw a 10x10 cm (!!) rectangle in Xara and export it as PNG with 300dpi, you get a ~40x40 cm rectangle with 72dpi in Photoshop.
If, in Photoshop, you choose Image - Image Size, UNCHECK "resample image" and then change the dpi to 300, you'll end up with a 10x10 cm rectangle with 300dpi like you wanted it.
It's weird behaviour, but in the end it works perfect.

As said, you can avoid all this by using TIF instead.

Wolfgang

[Sean Sedwards]

I'm sure there are some red faces at Xara Ltd about this bug. To save time, however, you can create a 24-bit bitmap copy on the page and then simply copy & paste it into PhotoShop.

Regards - Sean

[Mark Goodall]

This is a problem with photoshop. It converts all PNG ( and presumably other) bitmaps with non-72dpi into 72dpi bitmaps and converts the dimensions accordingly. This is because presumably, being a bitmap app, it wants a 1-1 mapping of image to screen pixels.
Load the PNG created in Xara and load into a non-bitmap app ( e.g. Xara, CorelDraw, Illustrator) and you will see that the correct dimensions and resolution are retained.
There are no red faces here.

Mark Goodall
Xara Ltd

[Klaus Nordby]

Wolfgang: "If, in Photoshop, you choose Image - Image Size, UNCHECK "resample image" and then change the dpi to 300, you'll end up with a 10x10 cm rectangle with 300dpi like you wanted it.
It's weird behaviour, but in the end it works perfect."

Wolfgang, you are totally right about this procedure. But there is NOTHING weird about it: DPI settings are wholly nominal, arbitrary values - the only REAL values in any bitmap file are the numbers of horizontal and vertical pixels and their color depth. And since Photoshop never meddles with these values on importing a bitmap, there is never any REAL problem here - neither in XaraX's export nor in PS's import.


K

[Wolfgang]

Klaus,

you got me wrong with the "weird" behavior. Mark already answered why it happens and that was what I called weird.

I meant, that the 'conversion' done by Photoshop is weird, not the relation between dpi and pixels.

In fact, I have to explain the needlessness (if there is such a word) of dpi when it comes to screen design every day to my customers.

Still I don't understand why Photoshop does this. It works as it should with TIF, so Mark's presumption can't be the reason ..

Wolfgang

[Sean Sedwards]

I should have looked at the file instead of just testing it with Picture Publisher 7 which, I discover, has the same problem as PhotoShop 4! It seems that PNGs are being treated as web graphics that don't use dpi (like GIF), but it would be surprising if more recent versions perpetuate that myth. Other bitmap file formats work fine in PP and PS, although I've discovered that Paint Shop Pro 5 doesn't accept dpi information on the clipboard.

Regards - Sean