Autodesk help - Image size limits

[Anonymous]

My previous post on this subject has not drawn any response. Hopefully
someone from Autodesk will answer this one.

I am using Autocad Map 2000i on a PIII with a 20Gb hardrive and 128Mb RAM.
There is 12 GB free on the hard drive. The OS is Win98 2nd Ed.

I am trying to insert 4 jpegs into a new drawing which as yet has no vector
content. 3 of the jpegs are about 55Mb in size and the 4th is 24Mb in size.
These are tiles of a digital orthophoto - not particularly big images. I
assumed Map would not hesitate to load these. It does hesitate.

3 files load perfectly with their georeferenceing intact. Only the frame of
the fourth image is visible and a message appears on the command line saying
that there is O space left on drive C and I must free more space. The
message also says 889100Kb required.

If I check the disk space available at this point it is 10Gb. This leads me
to beleive that Map has used 2Gb for an image swap file. The sum of the
sizes of my images is only about 189Mb. Could this occupy 2Gb of swap file
space ? And whys does Map not find the remaining 10Gb free hard drive space
?

PLEASE help anybody !!! I'm getting desperate.

Thanks
Mark Straughan

[DWalsh]

FBV,

I cannopt help you directly, but I suggest you try and post this request on the CAD Overlay group, and see if you get any responses. CAD Overlay uses the same engine as map to worlk with images, and that newsgroup is dedicated to working with images.

Sorry I can't help more,
David Walsh

[Anonymous]

Thanks David. I have reposted there.

Mark

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DWalsh <
href="mailto:david.walsh@autodesk.com">david.walsh@autodesk.com> wrote
in message
href="news:f072a93.0@WebX.maYIadrTaRb">news:f072a93.0@WebX.maYIadrTaRb...

FBV,

I cannopt help you directly, but I suggest you try and post this request on
the CAD Overlay group, and see if you get any responses. CAD Overlay uses the
same engine as map to worlk with images, and that newsgroup is dedicated to
working with images.

Sorry I can't help more,
David Walsh

[Anonymous]

Mark,

you're right with your assumption that the swap file cannot be bigger than 2 GB.
Cad Overlay's image engine (which lies behind the Map imaging functionality)
will ignore any bigger value that might have been set in the options dialog.
JPG is a compressed raster file format, but for the insertion Map needs to
uncompress the files. That makes your swap file exceeding the limit so quickly.

Workarounds:
You could try if a not or less compressed format (for instance a non-compressed
TIFF) needs less space than an umcompressed JPG.
Another option would be to upgrade to Map 2002 R 5.0 which supports ECW (MrSid)
format that has a more intelligent display mangement using less memory.
A last idea would be to save each single raster file in a separate dwg, then
attach this dwgs and query only the needed raster file into the current work
session.

Marion Pietsch
WW Support & Services
Autodesk GIS Product Support

FBV wrote:

> My previous post on this subject has not drawn any response. Hopefully
> someone from Autodesk will answer this one.
>
> I am using Autocad Map 2000i on a PIII with a 20Gb hardrive and 128Mb RAM.
> There is 12 GB free on the hard drive. The OS is Win98 2nd Ed.
>
> I am trying to insert 4 jpegs into a new drawing which as yet has no vector
> content. 3 of the jpegs are about 55Mb in size and the 4th is 24Mb in size.
> These are tiles of a digital orthophoto - not particularly big images. I
> assumed Map would not hesitate to load these. It does hesitate.
>
> 3 files load perfectly with their georeferenceing intact. Only the frame of
> the fourth image is visible and a message appears on the command line saying
> that there is O space left on drive C and I must free more space. The
> message also says 889100Kb required.
>
> If I check the disk space available at this point it is 10Gb. This leads me
> to beleive that Map has used 2Gb for an image swap file. The sum of the
> sizes of my images is only about 189Mb. Could this occupy 2Gb of swap file
> space ? And whys does Map not find the remaining 10Gb free hard drive space
> ?
>
> PLEASE help anybody !!! I'm getting desperate.
>
> Thanks
> Mark Straughan

[Anonymous]

Hi Mark,

The solution is quite simple.  You must create
"Tiled TIFFs" out of your individual images.  When you do that, the image
itself is being used as a swap file, hence, very little space will be used up on
your HDD, and you won't reach the magic 2GB limit.

I have assembled mosaics with over 190,
40mb-160mb images.  The drawing still takes a while to load, but
the space required on your HDD is only 100mb +/-

To create a Tiled TIFF follow these
steps:

1. Start Autocad with a blank drawing

2. insert the first image  (if your drawing
template file is metric, you must set the image units to meters on
insertion)

3. Zoom Extents

4. Image pulldown menu -> select IMAGE
-> WRITE -> EXPORT -> Tiled TIFF -> Macpaint BITS -> Write
Correlation -> World File 

5. Now the image is saved as a Tiled TIFF. 
You may want to create a new directory where you keep the TILED
Images.

6. Repeat 1-6 for all images you want to
use.

7. Insert all new TILED IMAGES into one
drawing.

8. You're done.

Don't hesitate to email me if there is a problem
with the instructions above.  I am trying to recall it from
memory.

Martin Sladek

Bergetti Computers

href="http://www.bergetti.com">http://www.bergetti.com

href="mailto:martin@bergetti.com">martin@bergetti.com