SaveAsByteArray: optimize ?

[ctn]

Hi

If I perform safe a image after scan (SaveAsByteArray) with 600dpi color and BMP/TIFF as byte array (in memory) it takes too long (more that 10 min.).
Is it somehow possible to optimize this process?

Thank you
Br,
Toan

[Loïc]

it takes too long (more that 10 min.).

Hum... I am a bit surprised. Could you give me some of line of code ?

Best regards,

Loïc

[ctn]

Sorry, it takes more than 8min. After more than 8 minutes I got a communcation timeout (CommunicationException).

System information: WinXP, Intel Core(TM)2 Duo CPU 2.10 GHz, 3GB RAM
Please find below the code sample: Test with 600dpi, BMP format

Code: Select all

[b]   byte[] imageBytes = new byte[0];
   int nBytesRead = imageBytes.Length;[/b]

   // Save to byte array check
   DateTime start = DateTime.Now;
   _logger.logDebug("imageOrPreviewScan(): save to byte array timer start time --> {0}", start);

   [b]_gdTwain.SaveAsByteArray(ref imageBytes, ref nBytesRead, imageFormat.ToString(), 0);[/b]

   DateTime end = DateTime.Now;
   _logger.logDebug("imageOrPreviewScan(): save to byte array timer stop time --> {0}", end);
   _logger.logDebug("imageOrPreviewScan(): save to byte array time elapsed: {0}", end - start);

[b]   image = new byte[imageBytes.Length];
   imageBytes.CopyTo(image, 0);[/b]


Logs:
imageOrPreviewScan(): save to byte array timer start time --> 02/06/2009 09:37:51
imageOrPreviewScan(): save to byte array timer stop time --> 02/06/2009 09:46:01
imageOrPreviewScan(): save to byte array time elapsed: 00:08:09.3663700

Br, ctn

[ctn]

Hi Loïc

Do you have any news about this issue?
Thanks
ctn

[Loïc]

Hi,

Saving a 600 DPI image as bitmap format is not a good idea.
I suggest you to use a format using compression schemes such as TIFF or JPEG. Your saving time should be dramatically decreased.


Best regards,

Loïc

[ctn]

The Data compression of TIFF is not much better. Also after more than 8 minutes I got a communication timeout:

imageOrPreviewScan(): save to byte array timer start time --> 02/11/2009 09:26:52
imageOrPreviewScan(): save to byte array timer stop time --> 02/11/2009 09:35:05
imageOrPreviewScan(): save to byte array time elapsed: 00:08:13.5526205

But JPEG is faster (~10 seconds for 7534771 Bytes):
imageOrPreviewScan(): save to byte array timer start time --> 02/11/2009 09:39:07
imageOrPreviewScan(): save to byte array timer stop time --> 02/11/2009 09:39:18
imageOrPreviewScan(): save to byte array time elapsed: 00:00:10.5055973

Br, ctn

[Loïc]

Hi,

For the tiff format you should select a compression scheme.

In all case I suggest you to use TIFF with CCITT4 compression for bitonal image and JPEG compression for color images.

With best regards,

Loïc