D 2014-10-31T15:08:45.674
L reference_table
P ab2607b0c7f13f10dd5ad8764e61c61b15b731c8
U sandro
W 20887
Back to <a href="https://www.gaia-gis.it/fossil/librasterlite2/wiki?name=rasterlite2-doc">RasterLite2 doc index</a><hr><br>
<h1>Supported sample types</h1>
<table width="100%" border="1" bgcolor="#fffff0" cellpadding="6" cellspacing="4">
<tr><th bgcolor="#f0f0f0">Family</th><th bgcolor="#f0f0f0">Bits</th><th bgcolor="#f0f0f0">Mnemonic</th><th bgcolor="#f0f0f0">Notes</th></tr>
<tr><td rowspan="6" align="center">Unsigned Integer</td>
<td align="center">1</td>
<td align="center"><b>1-BIT</b></td>
<td><table>
<tr><td>Min value: 0</td></tr>
<tr><td>Min value: 1</td></tr>
</table></td></tr>
<tr><td align="center">2</td>
<td align="center"><b>2-BIT</b></td>
<td><table>
<tr><td>Min value: 0</td></tr>
<tr><td>Min value: 3</td></tr>
</table></td></tr>
<tr><td align="center">4</td>
<td align="center"><b>4-BIT</b></td>
<td><table>
<tr><td>Min value: 0</td></tr>
<tr><td>Min value: 15</td></tr>
</table></td></tr>
<tr><td align="center">8</td>
<td align="center"><b>UINT8</b></td>
<td><table>
<tr><td>Min value: 0</td></tr>
<tr><td>Min value: 255</td></tr>
</table></td></tr>
<tr><td align="center">16</td>
<td align="center"><b>UINT16</b></td>
<td><table>
<tr><td>Min value: 0</td></tr>
<tr><td>Min value: 65,535</td></tr>
</table></td></tr>
<tr><td align="center">32</td>
<td align="center"><b>UINT32</b></td>
<td><table>
<tr><td>Min value: 0</td></tr>
<tr><td>Min value: 4,294,967,295</td></tr>
</table></td></tr>
<tr><td rowspan="3" align="center">Signed Integer</td>
<td align="center">8</td>
<td align="center"><b>INT8</b></td>
<td><table>
<tr><td>Min value: -128</td></tr>
<tr><td>Min value: 127</td></tr>
</table></td></tr>
<tr><td align="center">16</td>
<td align="center"><b>INT16</b></td>
<td><table>
<tr><td>Min value: -32,768</td></tr>
<tr><td>Min value: 32,767</td></tr>
</table></td></tr>
<tr><td align="center">32</td>
<td align="center"><b>INT32</b></td>
<td><table>
<tr><td>Min value: -2,147,483,648</td></tr>
<tr><td>Min value: 2,147,483,647</td></tr>
</table></td></tr>
<tr><td rowspan="2" align="center">Floating Point</td>
<td align="center">32</td>
<td align="center"><b>FLOAT</b></td>
<td><table>
<tr><td>Min value: -3.402823e+038</td></tr>
<tr><td>Min value: 3.402823e+038</td></tr>
</table></td></tr>
<tr><td align="center">64</td>
<td align="center"><b>DOUBLE</b></td>
<td><table>
<tr><td>Min value: -1.797693e+308</td></tr>
<tr><td>Min value: 1.797693e+308</td></tr>
</table></td></tr>
</table><br>
<hr>
<h1>Supported pixel types</h1>
<table width="100%" border="1" bgcolor="#fffff0" cellpadding="6" cellspacing="4">
<tr><th bgcolor="#f0f0f0">Mnemonic</th><th bgcolor="#f0f0f0">Bands</th><th bgcolor="#f0f0f0">Sample type</th><th bgcolor="#f0f0f0">Notes</th></tr>
<tr><td align="center"><b>MONOCHROME</b></td>
<td align="center">1</td>
<td align="center"><b>1-BIT</b></td>
<td>the implicit photometric interpretation always is:
<ul>
<li><b>0</b>: full transparent</li>
<li><b>1</b>: black, opaque</li>
</td></tr>
<tr><td align="center"><b>PALETTE</b></td>
<td align="center">1</td>
<td align="center"><b>1-BIT</b><br><b>2-BIT</b><br><b>4-BIT</b><br><b>UINT8</b></td>
<td>the implicit photometric interpretation is always the one defined by the Palette Color associated to the Raster Coverage.<br>
This actually corresponds to an RGB output image, the color of each pixel being indirectly determined by its palette index.
</td></tr>
<tr><td align="center"><b>GRAYSCALE</b></td>
<td align="center">1</td>
<td align="center"><b>2-BIT</b><br><b>4-BIT</b><br><b>UINT8</b></td>
<td>the implicit photometric interpretation is always of the Grayscale type.<br>
<b>0</b> always corresponds to full black, and the max value to full white.
</td></tr>
<tr><td align="center"><b>RGB</b></td>
<td align="center">3</td>
<td align="center"><b>UINT8</b><br><b>UINT16</b></td>
<td>the implicit photometric interpretation is always of the RGB type.
</td></tr>
<tr><td align="center"><b>MULTIBAND</b></td>
<td align="center">> 1<br>< 256</td>
<td align="center"><b>UINT8</b><br><b>UINT16</b></td>
<td>there is no implicit photometric interpretation.
</td></tr>
<tr><td align="center"><b>DATAGRID</b></td>
<td align="center">1</td>
<td align="center"><b>INT8</b><br><b>UINT8</b><br><b>INT16</b><br><b>UINT16</b><br><b>INT32</b><br><b>UINT32</b><br><b>FLOAT</b><br><b>DOUBLE</b></td>
<td>there is no implicit photometric interpretation.
</td></tr>
</table><br>
<hr>
<h1>Supported compression algorithms</h1>
<table width="100%" border="1" bgcolor="#fffff0" cellpadding="6" cellspacing="4">
<tr><th bgcolor="#f0f0f0">Mnemonic</th><th bgcolor="#f0f0f0">Compression type</th><th bgcolor="#f0f0f0">Notes</th></tr>
<tr><td align="center"><b>NONE</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>no compression at all: simply an array of tightly packed values.
</td></tr>
<tr><td align="center"><b>DEFLATE</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>a general purpose compression algorithm used by ZIP archives and implemented by <a href="http://en.wikipedia.org/wiki/Zlib">zlib</a>.<br>
You can find more detailed information about this algorithm <a href="http://en.wikipedia.org/wiki/DEFLATE">here</a>.
</td></tr>
<tr><td align="center"><b>DEFLATE_NO</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>Exactly the same as <b>DEFLATE</b> except in that it will never apply a <b>Delta Filter</b>.
</td></tr>
<tr><td align="center"><b>LZMA</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>an advanced general purpose compression algorithm used by 7-ZIP archives and implemented by <a href="http://en.wikipedia.org/wiki/XZ_Utils">liblzma</a>.<br>
You can find more detailed information about this algorithm <a href="http://en.wikipedia.org/wiki/Lempel%E2%80%93Ziv%E2%80%93Markov_chain_algorithm">here</a>.<br>
<u>Please note</u>: this algorithm is very slow while compressing, but is reasonably fast while decompressing; and usually ensures better compression ratios than DEFLATE.</li>
</td></tr>
<tr><td align="center"><b>LZMA_NO</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>Exactly the same as <b>LZMA</b> except in that it will never apply a <b>Delta Filter</b>.
</td></tr>
<tr><td align="center"><b>FAX4</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>an highly specialized compression algorithm only supporting monochrome images initially developed for fax machines: implemented by <a href="http://en.wikipedia.org/wiki/Libtiff">libtiff</a>.
You can find more detailed information about this algorithm <a href="http://en.wikipedia.org/wiki/Group_4_compression">here</a>.
</td></tr>
<tr><td align="center"><b>PNG</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>a very popular general purpose image format supporting RGB, Grayscale and Palette-based colorspaces and fully supporting transparencies. Implemented by <a href="http://en.wikipedia.org/wiki/Libpng">libpng</a>.<br>
You can find more detailed information about this compressed format <a href="http://en.wikipedia.org/wiki/Portable_Network_Graphics">here</a>.
</td></tr>
<tr><td align="center"><b>JPEG</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossy_compression">lossy</a></b></td>
<td>an universally spread photographic image format supporting RGB and Grayscale colorspaces but completely lacking of any transparency support. Implemented by <a href="http://en.wikipedia.org/wiki/Libjpeg">libjpeg</a>.<br>
You can find more detailed information about this compressed format <a href="http://en.wikipedia.org/wiki/JPEG">here</a>.
</td></tr>
<tr><td align="center"><b>WEBP</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossy_compression">lossy</a></b></td>
<td>an innovative photographic image format supporting RGB and Grayscale colorspaces and fully supporting transparencies. Implemented by <a href="https://code.google.com/p/webp/downloads/detail?name=libwebp-0.4.0.tar.gz">libwebp</a>.<br>
You can find more detailed information about this compressed format <a href="http://en.wikipedia.org/wiki/WebP">here</a>.<br>
<u>Please note</u>: this algorithm is very slow while compressing, but is reasonably fast while decompressing; and usually ensures slightly better compression ratios than JPEG at the same quality level.</li>
</td></tr>
<tr><td align="center"><b>LL_WEBP</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>exactly the same of the previous one, but in <b><i>lossless</i></b> mode.<br>
This usually means accepting moderate compression ratios (about 1:2).
</td></tr>
<tr><td align="center"><b>CHARLS</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>a genuinely <b><i>lossless</i></b> compression based on the <a href="http://en.wikipedia.org/wiki/Lossless_JPEG">JPEG-LL</a> algorithm (don't be confused; it's a completely different algorithm from the usual JPEG).<br>
It usually ensures good compression factors (about 1:2) and it's reasonably fast.
</td></tr>
<tr><td align="center"><b>JP2</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossy_compression">lossy</a></b></td>
<td>the <a href="http://en.wikipedia.org/wiki/JPEG_2000">Jpeg2000</a> photographic image format supporting RGB and Grayscale colorspaces and fully supporting transparencies. Implemented by <a href="http://www.openjpeg.org/"> OpenJpeg</a>.<br>
<u>Please note</u>: this algorithm is very slow either while compressing and compressing; it usually ensures slightly better compression ratios than JPEG at the same quality level.</li>
</td></tr>
<tr><td align="center"><b>LL_JP2</b></td>
<td align="center"><a href="http://en.wikipedia.org/wiki/Lossless_data_compression">lossless</a></b></td>
<td>exactly the same of the previous one, but in <b><i>lossless</i></b> mode.<br>
This usually means accepting moderate compression ratios (about 1:2).
</td></tr>
</table><br>
<hr>
<h1>Pixel / Sample / Compression compatibility chart</h1>
<table width="100%" cellpadding="6" cellspacing="4">
<tr><th rowspan="2"></th>
<th bgcolor="#d0d0d0" valign="top">MONOCHROME</th>
<th bgcolor="#d0d0d0" valign="top">PALETTE</th>
<th bgcolor="#d0d0d0" valign="top">GRAYSCALE</th>
<th bgcolor="#d0d0d0" valign="top" colspan="2">RGB</th>
<th bgcolor="#d0d0d0" valign="top" colspan="3">MULTIBAND</th>
<th bgcolor="#d0d0d0" valign="top" colspan="2">DATAGRID</th></tr>
<tr><th bgcolor="#e0e0d0" valign="top">1-BIT</b></th>
<th bgcolor="#e0e0d0" valign="top">1-BIT<br>2-BIT<br>4-BIT<br>UINT8</th>
<td bgcolor="#e0e0d0" valign="top" align="center"><b>2-BIT<br>4-BIT<br>UINT8</b><br><br><hr><i>for Grayscale 16bit please see</i>:<br>DATAGRID UINT16</td>
<th bgcolor="#e0e0d0" valign="top">UINT8</th>
<th bgcolor="#e0e0d0" valign="top">UINT16</th>
<td bgcolor="#e0e0d0" valign="top" align="center"><b>UINT8</b><br><br><br><hr><i>(3 or 4 bands)</i></td>
<td bgcolor="#e0e0d0" valign="top" align="center"><b>UINT16</b><br><br><br><hr><i>(3 or 4 bands)</i></td>
<td bgcolor="#e0e0d0" valign="top" align="center"><b>UINT8</b><br><b>UINT16</b><br><br><hr><i>(2 or >= 5 bands)</i></td>
<th bgcolor="#e0e0d0" valign="top">UINT8<br>UINT16</th>
<th bgcolor="#e0e0d0" valign="top">INT8<br>INT16<br>INT32<br>UINT32<br>FLOAT<br>DOUBLE</th></tr>
<tr><th bgcolor="#d0d0d0">NONE</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
</tr>
<tr><th bgcolor="#d0d0d0">DEFLATE</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
</tr>
<tr><th bgcolor="#d0d0d0">DEFLATE_NO</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
</tr>
<tr><th bgcolor="#d0d0d0">LZMA</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
</tr>
<tr><th bgcolor="#d0d0d0">LZMA_NO</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
</tr>
<tr><th bgcolor="#d0d0d0">FAX4</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>
</tr>
<tr><th bgcolor="#d0d0d0">PNG</th>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
</tr>
<tr><th bgcolor="#d0d0d0">JPEG</th>
<td></td><td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td><td></td><td></td><td></td><td></td><td></td>
</tr>
<tr><th bgcolor="#d0d0d0">WEBP</th>
<td></td><td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td><td></td>
</tr>
<tr><th bgcolor="#d0d0d0">LL_WEBP</th>
<td></td><td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td><td></td>
</tr>
<tr><th bgcolor="#d0d0d0">CHARLS</th>
<td></td><td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
</tr>
<tr><th bgcolor="#d0d0d0">JP2</th>
<td></td><td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
</tr>
<tr><th bgcolor="#d0d0d0">LL_JP2</th>
<td></td><td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
<td bgcolor="#d0ffd0" align="center">yes</td>
<td></td>
</tr>
</table>
<br>
<hr>
<h1>Multi-resolution Pyramid levels configuration</h1>
<table width="100%" cellpadding="6" cellspacing="4">
<tr><th bgcolor="#d0d0d0">Pixel type</th><th bgcolor="#d0d0d0">Base level<br><i>full resolution</i></th><th bgcolor="#d0d0d0">Upper levels<br><i>rescaled</i></th><th bgcolor="#d0d0d0" valign="center" width="50%">Notes</th></tr>
<tr><th bgcolor="#e0e0d0">MONOCHROME</th><th bgcolor="#d0ffd0">1-BIT</th><th bgcolor="#e0ffff">GRAYSCALE UINT8<br><i>compression</i> PNG</th><td>applying an high-quality <b><i>halftone interpolation</i></b> rescaling/downsampling algorithm ensures a better visual quality but imposes a change in color model.</tr>
<tr><th bgcolor="#e0e0d0" rowspan="4">PALETTE</th><th bgcolor="#d0ffd0">1-BIT</th><th bgcolor="#e0ffff">RGB UINT8<br><i>compression</i> PNG</th><td>same as above</td></tr>
<tr><th bgcolor="#d0ffd0">2-BIT</th><th bgcolor="#e0ffff">RGB UINT8<br><i>compression</i> PNG</th><td>same as above</td></tr>
<tr><th bgcolor="#d0ffd0">4-BIT</th><th bgcolor="#e0ffff">RGB UINT8<br><i>compression</i> PNG</th><td>same as above</td></tr>
<tr><th bgcolor="#d0ffd0">UINT8</th><th bgcolor="#e0ffff">RGB UINT8<br><i>compression</i> JPEG</th><td>same as above</td></tr>
</tr>
<tr><th bgcolor="#e0e0d0" rowspan="3">GRAYSCALE</th><th bgcolor="#d0ffd0">2-BIT</th><th bgcolor="#e0ffff">GRAYSCALE UINT8<br><i>compression</i> JPEG</th><td>same as above</td></tr>
<tr><th bgcolor="#d0ffd0">4-BIT</th><th bgcolor="#e0ffff">GRAYSCALE UINT8<br><i>compression</i> JPEG</th><td>same as above</td></tr>
<tr><th bgcolor="#d0ffd0">UINT8</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#e0e0d0" rowspan="2">RGB</th><th bgcolor="#d0ffd0">UINT8</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">UINT16</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
</tr>
<tr><th bgcolor="#e0e0d0" rowspan="2">MULTIBAND</th><th bgcolor="#d0ffd0">UINT8</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">UINT16</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#e0e0d0" rowspan="8">DATAGRID</th><th bgcolor="#d0ffd0">INT8</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">UINT8</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">INT16</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">UINT16</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">INT32</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">UINT32</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">FLOAT</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
<tr><th bgcolor="#d0ffd0">DOUBLE</th><th bgcolor="#d0ffd0"><i>same as in base-level</i></th></tr>
</table>
<ol>
<li>the same identical <b>PixelType</b>, <b>SampleType</b> and <b>Compression</b> are adopted for both base-level and upper rescaled-levels whenever is possible.</li>
<li> except when a change in the color space is strictly required by high-quality rescaling/downsampling algorithm supporting <b><i>halftone interpolation</i></b>.</li>
<li>all upper Pyramid levels (rescaled) are always implicitly compressed: these are always heavily reworked levels, so there is any real need to carefully preserve all input data exactly as they originally were.</li>
<ul>
<li><b>JPEG</b> is used for either RGB and GRAYSCALE (UINT8).</li>
<li><b>PNG</b> is used for all limited extension samples: 1-BIT, 2-BIT and 4-bit.<br>All these samples could implicitly imply <b><i>transparency</i></b>, and only PNG will offer an adequate support.</li>
<li><b>DEFLATE</b> is used for any other configuration.</li>
</ul></li>
</ol>
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