<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am new to using virtual slides and openslide library to access these files. I have a few Aperio (.svs) files that I could open with open slide. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>My question is how is the aggregation done at multiple levels. I see that the aggregation RGB of 4x4 grid is not the 1x1 grid at the higher level (my down sampling is ~4). I have attached a small snippet of the code for reference. Can someone please explain how the aggregation is done across multiple levels? <o:p></o:p></p><p class=MsoNormal>Otherwise, can you please direct me to documentation which will help me understand this aggregation<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thank you for your help.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sriram<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Code:<o:p></o:p></p><p class=MsoNormal>openslide_read_region(slide, buf, 0, 0, 0, 4, 4);<o:p></o:p></p><p class=MsoNormal>openslide_read_region(slide, buf1, 0, 0, 1, 1, 1);<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Output:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>4x4 grid at level 0:<o:p></o:p></p><p class=MsoNormal>The level 0 width 107046, the height 87978<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 239, green 239, blue 239<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>1x1 grid at level 1:<o:p></o:p></p><p class=MsoNormal>The level 1 width 26761, the height 21994<o:p></o:p></p><p class=MsoNormal>The alpha 255, red 241, green 241, blue 239<o:p></o:p></p></div></body></html>