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#1 Posted : Monday, March 30, 2009 9:04:28 AM(UTC)

daub815  
daub815

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I am doing a test with a jpeg2000 image (http://memory.loc.gov/gmd/gmd412/g4127/g4127l/ct001114.jp2), but am getting an odd result.  Here is my code for loading the JPEG2000 and converting it to an ImageSource:

                    RasterImage rasterImg = codecs.Load(this.m_url);
                    ImageSource img = Leadtools.Windows.Media.RasterImageMediaConverter.ConvertFrom(rasterImg, RasterImageMediaConverterFromFlags.None));

But when I look at the sizes of the rasterImg and the img they are not the same  The RasterImage is 6354 (width) by 3926 (height) and the ImageSource is 4066.56 (width) by 2512.64 (height).  At a glance, I don't see any pixel loss.  Is the image just being resized because the ImageSource can only hold a certain image size?  Why are they different sizes?
 

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#2 Posted : Tuesday, March 31, 2009 6:34:13 AM(UTC)

Adam Boulad  
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When you convert an image from a LEAD RasterImage to an ImageSource, the dimensions of the image are converted to the resolution units of the display, which are by default 96 dots per inch (DPI).

The image you tested does not have a DPI resolution value stored in it. When you load it into LEADTOOLS, it is given a default resolution value of 150 DPI.
This means its dimensions in inches are considered to be 42.36 x 26.17 inches.

These values correspond to the following dimensions at 96 DPI:
width = 6354/150.0*96 = 4066.56
height = 3926/150.0*96 = 2512.64
 
#3 Posted : Tuesday, March 31, 2009 6:40:33 AM(UTC)

daub815  
daub815

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So when I do the conversion, can I specify the DPI?  Thanks for your response.  It definitely explains my results.
 
#4 Posted : Tuesday, March 31, 2009 11:03:02 PM(UTC)

Adam Boulad  
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After you load the image, you can set the rasterImg.XResolution and rasterImg.YResolution to the screen DPI (which is usually 96).

 
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