Databases
StackOverflow2013
Postsdbo
POSystem.Drawing.Image Save() producing inconsistent file sizes
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POSystem.Drawing.Image Save() producing inconsistent file sizes
    primarykey
    data
    text
    <p>While converting TIFFs to PDFs, I noticed some of the PDFs were corrupted. After some research, it appears the problem is in the System.Drawing.Image class. To test this, instead of converting to PDFs, I had the program just read in the image files and re-save them. Some of the newly saved files have inconsistent file sizes between different runs of the program. The basic steps are:</p> <ol> <li>I read a TIFF image into a byte array. </li> <li>I use the System.Drawing.Image.FromStream() method to create an image object from the byte array. </li> <li>I then call the System.Drawing.Image.Save(stream) method to save the image to a new stream.</li> <li>I then examine the length of the stream.ToArray() method.</li> </ol> <p>The same input file results in a different output length between successive program executions. The output length varies by a couple hundred bytes. In addition, the resulting output length is more than twice the size of the input length, but I assume this is due to compression, or lack thereof. I am running this on windows 7 32-bit with .net 4.</p> <p>Why might the output length vary like this?</p> <p>UPDATE:</p> <p>After reviewing this connect issue (<a href="https://connect.microsoft.com/VisualStudio/feedback/details/584681/system-drawing-image-flags-has-different-value-in-vista-and-windows-7" rel="nofollow">https://connect.microsoft.com/VisualStudio/feedback/details/584681/system-drawing-image-flags-has-different-value-in-vista-and-windows-7</a>) and the community comment on this MSDN page (<a href="http://msdn.microsoft.com/en-us/library/system.drawing.image.save.aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/system.drawing.image.save.aspx</a>), it appears the issue is related to an operating system level bug in Windows 7. Can anyone confirm this or offer a workaround?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USNYSystemsAnalyst
    1. USNYSystemsAnalyst
    plurals
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COGDI+, the native Windows component that's wrapped by the classes in System.Drawing was updated at Vista time from version 1.0 to version 1.10. Lots of fixes, none of them documented in detail. Tiff has never not been a problem, it didn't get its "thousands of incompatible file formats" nick by accident. You didn't document sufficient details to offer a real answer. Companies like LeadTools make a good living offering competitive solutions.
      singulars
      1. POSystem.Drawing.Image Save() producing inconsistent file sizes
      1. USHans Passant
    2. COWhat details should I offer? The images I'm working with are 1bpp TIFF images with /CCITT T.6 compression. When debugging on Windows XP, the Image.Flags property is set to 77888 indicating a grayscale image, which is correct. On Windows 7, the Flags property is set to 77840 indicating an RGB image, which is incorrect.
      singulars
      1. POSystem.Drawing.Image Save() producing inconsistent file sizes
      1. USNYSystemsAnalyst
    3. CONYSystemsAnalyst - I am working on a low cost command line tool/library to do this type of conversion (much much faster than libtiff and anything .NET can do). If you'll help iron out any last issues, you can be a free customer. Please contact me if interested.
      singulars
      1. POSystem.Drawing.Image Save() producing inconsistent file sizes
      1. USBitBank
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload