<html 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=Windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:DengXian;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:DengXian;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:SimSun;
panose-1:2 1 6 0 3 1 1 1 1 1;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
text-align:justify;
text-justify:inter-ideograph;
font-size:10.5pt;
font-family:DengXian;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
.MsoChpDefault
{mso-style-type:export-only;}
/* Page Definitions */
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="ZH-CN" link="blue" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span lang="EN-US">Hi guys. Have a nice day.</span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I’m curious how gdal scales the values when converting from a larger range to a smaller range,like from u32 to u8, u16 to u8, f32 to u8 etc..</span></p>
<p class="MsoNormal"><span lang="EN-US">I made a test:</span></p>
<p class="MsoNormal" style="text-indent:21.0pt"><span lang="EN-US">gdal_translate -ot Byte -of GTiff gray_u32.tif gray_u8.tif
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">All the u32 value in every sample of my gray_u32.tif is 10050</span></p>
<p class="MsoNormal"><span lang="EN-US">And All the value in result file is 255.</span></p>
<p class="MsoNormal"><span lang="EN-US">This seems to be a boundary case where the maximum and minimum values are both 10050 but I’m curious the behavior here and I didn’t find a doc about this.</span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I hope this question is not too suptid or weired.</span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Best, Lucas </span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:12.0pt;font-family:SimSun"><o:p> </o:p></span></p>
</div>
</body>
</html>