Big Images

[Sheff]

I am crashing Xara when I try to export 24in x 36 in 300 dpi images with true color and alpha.

I get out of memory errors, even though I have 1 gig of memory.

I need a resolution. Can anyone help?

Sheffield Abella
sheff@sheff.com
www.sheff.com

[Sheff]

I am crashing Xara when I try to export 24in x 36 in 300 dpi images with true color and alpha.

I get out of memory errors, even though I have 1 gig of memory.

I need a resolution. Can anyone help?

Sheffield Abella
sheff@sheff.com
www.sheff.com

[Sean Sedwards]

A 32 bit uncompressed bitmap of the size and dpi you describe requires about 300Mb of memory or disk space. Although the file size of a PNG will be smaller, it requires at least as much memory because it's stored as a BMP and Xara needs extra to render and compress it.

Make sure you have adequate disk space for saving the file (assume 300Mb) and adequate temporary disk space in ..\Windows\Temp (assume 300Mb again, 600Mb in total if on the same drive). Remove all bitmaps and bitmap copies not part of the drawing and close other drawings and applications. If that doesn't work, you may have to export the alpha channel separately and recombine it in a bitmap app. Try exporting as a 24 bit BMP or (uncompressed) TIFF, which use more disk space but require less memory. Use only 256 colours for the alpha channel.

Let us know how you get on. There may be other options.

Regards - Sean

[Sean Sedwards]

Try creating a 32 bit bitmap copy of your artwork and save as a PNG from the Bitmap Gallery. It's just possible that separating the creation and exporting phases will do the trick.

Regards - Sean

[Sheff]

Usually I put a box around the entire drawing and give it it's own layer. Then I select only the layer of what I want to export and the box layer so I have 2 objects on 2 layers selected. Then I export the PNG. That way, I'm assured that the exported PNGs line up when I import them in Photoshop.

The images were too big so what I did was export whole image as a tif. Then I exported each object by itself as a PNG then I used the tiff to guide the alignment in Photoshop.

What choked the machine was I had created lightning by making a brush from an oval that had a elliptical gradient fill with elliptical transparency and feathering. When ever I tried to export that I would get an Out of Memory message. So I tried creating a bitmap copy of it (4 lines with these attributes) then giving that bitmap gradient transparency. That too choked the machine.

I ended up exporting the bitmap and giving it a layer mask in Photoshop. It worked fine.

But thanks Sean, I know I can always rely on you for help. You came up with solutions that hadn't occured to me.

I will post the the image when I get back from the client meeting.

Sheffield Abella
sheff@sheff.com
www.sheff.com

[standay]

I needed to export some round logos at about 24" diameter final size, 250 DPI. I was unable to export them as TIFs at that size and resolution, but I was able to export them that size and resolution as JPG files (about 6000 pixels by 6000 pixels according to the export dialog). I've sent an email to Xara about needing to be able to eport larger TIF image sizes but never got a response. Hopefully they are looking at this.

Stan

[tad]

A while back, one of the Xara team posted an inquiry as to whether we thought it important to be able to work with "large" images. Many of us replied YES !

In fact, those of you who work with service bureaus probably know that they have dedicated programs for enlarging images. Often these are part of their RIP and cost thousands of $$.

I suspect that coding for large images is no small matter (Sean could probably tell us), but if Xara could handle images up to 4feet x 8feet it would sure be worth a lot more than they are charging for the program now. I would be eager to purchase a "plug-in" or "enhanced" dll to enable large imaging. Even if it cost double (or more) the original cost of Xara.

Perhaps a poll is in order? And perhaps those more knowledgable than me can give us more information on solutions, programs & workarounds, for large imaging.

Regards,,,,Tad

[Sean Sedwards]

I'd say that the price of software sold to print bureaux reflects the limited market rather than the difficulty to implement it. The problems don't seem any greater than those solved by armies of programmers on early machines, trying to use more bits than the processor inherently supported.

X has a theoretical maximum page size of just under 1 mile square (1.5 x 1.5 Km), however it uses a practical limit of 9 x 9 feet. I'd guess that is the point some value in the rendering engine gets to 32 bits. It probably wouldn't be difficult to convert the algorithm to use 64 bits, but the cost would be to potentially double the rendering time. If my assumption is correct, Xara Ltd have traded the relatively few people who want pages bigger than 9 x 9 feet for the vast majority who want their 800 x 600 pixels rendered fast. Other than the fact that big drawings may contain more objects, I've found no problem working on an 8 x 4 feet page.

Creating or exporting large bitmaps requires large amounts of memory. A large swap file on disk (virtual memory) should be sufficient (1.16 Gb minimum, possibly 2 or 3 times that for an 8 x 4 ft, 24 bit, 300 dpi bitmap), however I'm not certain what proportion of real memory X would require. There may also be 32 bit limitations, as mentioned above, producing errors which appear to be memory related. I'd guess there are several layers of limitations, each relatively simple to cure, but formidable in total. The limited appeal and transportability of giant bitmaps is probably why Xara Ltd haven't tackled the problem.

Regards - Sean