<p>与你原来的标题（我更改了标题）不同，这不是一条“错误”信息，而只是一个警告：</p>
<pre><code>TIFFReadDirectory: Warning, Unknown field with tag 33550 (0x830e) encountered. [...]
TIFFReadDirectory: Warning, Unknown field with tag 33922 (0x8482) encountered. [...]
TIFFReadDirectory: Warning, Unknown field with tag 34735 (0x87af) encountered. [...]
[...]
</code></pre>
<p>这里列出的标签是GeoTIFF的<strong><a href="http://en.wikipedia.org/wiki/Tagged_Image_File_Format#Private_tags" rel="noreferrer">private tags</a></strong>。请看这里：</p>
<ul>
<li><a href="http://www.awaresystems.be/imaging/tiff/tifftags/private.html" rel="noreferrer">http://www.awaresystems.be/imaging/tiff/tifftags/private.html</a></li>
</ul>
<p>要查看它们的内容（对您来说可能不是很有意义），可以使用<code>tiffdump</code>（或<code>tiffutil -dump</code>）实用程序。有可能<code>exiftool</code>可以向您展示这些标记的含义：</p>
<pre><code> exiftool -a -U -u -g1 Yug-Shadedrelief.tmp.tif
</code></pre>
<p><code>-u</code>和<code>-U</code>也应该提取所有未知（to<code>exiftool</code>）标签。如果您的输出中没有“垃圾”，那么<code>exiftool</code>可以从它看到的东西中得出正面和反面，您也应该这样：-）</p>
<p>也许您可以选择<strike>释放</strike>删除这些标签<code>exiftool</code>也可以为您这样做</p>
<p>如果您只想让恼人的消息离开您的视线，而不想更改TIFF，那么为您的命令<code>2> /dev/null</code>重定向<em>stderr</em>就足够了：</p>
<pre><code>convert \
Yug-shadedrelief.tmp.tif \
-fuzz 7% \
-fill "#FFFFFF" \
-opaque "#DDDDDD" \
whited.jpg \
2>/dev/null
</code></pre>
<hr/>
<h2>更新</h2>
<pre><code> Code | Code | |
(dec) | (hex) | Tag Name | Short Description
+ -+ -+
33550 | 830E | ModelPixelScaleTag | Used in interchangeable GeoTIFF files
33922 | 8482 | ModelTiepointTag | Originally part of Intergraph's GeoTIFF,
34735 | 87af | GeoKeyDirectoryTag | Used in interchangeable GeoTIFF files
34736 | 87b0 | GeoDoubleParamsTag | Used in interchangeable GeoTIFF files
34737 | 87b1 | GeoAsciiParamsTag | Used in interchangeable GeoTIFF files
42113 | a481 | GDAL_NODATA | Used by GDAL lib, contains ASCII encoded nodata or ...
</code></pre>
<p><strong>解释：</strong></p>
<ul>
<li><strong><a href="http://www.awaresystems.be/imaging/tiff/tifftags/modelpixelscaletag.html" rel="noreferrer">33550</a>：</strong><em>“…可选用于定义光栅和模型空间之间的精确仿射变换…”</li>
<li><strong><a href="http://www.awaresystems.be/imaging/tiff/tifftags/modeltiepointtag.html" rel="noreferrer">33922</a>：</strong><em>“…也称为“地理参考标记”。此标记存储光栅->；模型连接点对…”</em></li>
<li><strong><a href="http://www.awaresystems.be/imaging/tiff/tifftags/geokeydirectorytag.html" rel="noreferrer">34735</a>：</strong><em>“…也称为‘ProjectionInfo标签’和‘CoordSystemInfoTag’”</em></li>
<li><strong><a href="http://www.awaresystems.be/imaging/tiff/tifftags/geodoubleparamstag.html" rel="noreferrer">34736</a>：</strong><em>“…用于存储GeoKeyDirectoryTag引用的所有双值GeoKey…”</em></li>
<li><strong><a href="http://www.awaresystems.be/imaging/tiff/tifftags/geoasciiparamstag.html" rel="noreferrer">34737</a>：</strong><em>“…用于存储GeoKeyDirectoryTag引用的所有ASCII值的地理键”</em></li>
<li><strong><a href="http://www.awaresystems.be/imaging/tiff/tifftags/gdal_nodata.html" rel="noreferrer">42113</a>：</strong><em>“…一种特殊的像素值，用于标记没有可用信息的地理空间区域……”</em></li>
</ul>
