In theory Scan2CAD will load any raster image up to 64,000 x 64,000 pixels in size for Windows XP and all later Operating System(OS) versions.

Windows OS versions earlier than Windows XP are restricted to 32,000 x 32,000 pixels in size. This equates approximately to a 13.3 foot x 13.3 foot or 4m x 4m drawing scanned at 200 dpi or a 6.6 foot x 6.6 foot or 2m x 2m drawing scanned at 400 dpi.

In practice the maximum image size that Scan2CAD will handle is determined by your PC’s system resources – for example the amount of physical and virtual RAM it has.

We recommend that you try to keep your raster images small to save disk space, resources and processing time. You can do this by:

Not scanning at an unnecessarily high resolution

200 to 400 dpi is optimal for most images.

For example, if you scan an E or A0 size drawing with a color depth of 2 at a resolution of 300 dpi it will take up about 16Mb of memory.

If you scan it at a resolution of 600 dpi it will take up about 64Mb of memory.

However, bear in mind that while you can decrease the resolution of an image after scanning, you cannot increase it. Therefore it can be better to err on the side of higher resolution.

Using the lowest possible color depth

For example, suppose you scan an E or A0 size drawing at 300 dpi.

If you scan it with a color depth of 2 it will take up about 16Mb of memory.

If you scan it with a color depth of 256 it will take up about 128Mb of memory.

If you scan it with a color depth of 16.7 million it will take up about 385Mb of memory.

If you try to open an image that is larger than 32,000 pixels in either width or height Scan2CAD will automatically split it into smaller more manageable “tiles” that you can vectorize separately.