TurboJPEG: Opt. enable progressive entropy coding

Fulfills part of the feature request in #153. Also paves the way for SIMD-accelerated progressive Huffman coding (refer to #46.)
2017-06-27 13:24:08 -05:00
parent 596e3965e7
commit aba6ae5950
11 changed files with 142 additions and 54 deletions
--- a/java/TJBench.java
+++ b/java/TJBench.java
@@ -627,6 +627,8 @@ class TJBench {
    System.out.println("     codec");
    System.out.println("-accuratedct = Use the most accurate DCT/IDCT algorithms available in the");
    System.out.println("     underlying codec");
+    System.out.println("-progressive = Use progressive entropy coding in JPEG images generated by");
+    System.out.println("     compression and transform operations.");
    System.out.println("-subsamp <s> = When testing JPEG compression, this option specifies the level");
    System.out.println("     of chrominance subsampling to use (<s> = 444, 422, 440, 420, 411, or");
    System.out.println("     GRAY).  The default is to test Grayscale, 4:2:0, 4:2:2, and 4:4:4 in");
@@ -726,6 +728,10 @@ class TJBench {
            System.out.println("Using most accurate DCT/IDCT algorithm\n");
            flags |= TJ.FLAG_ACCURATEDCT;
          }
+          if (argv[i].equalsIgnoreCase("-progressive")) {
+            System.out.println("Using progressive entropy coding\n");
+            flags |= TJ.FLAG_PROGRESSIVE;
+          }
          if (argv[i].equalsIgnoreCase("-rgb"))
            pf = TJ.PF_RGB;
          if (argv[i].equalsIgnoreCase("-rgbx"))
--- a/java/doc/constant-values.html
+++ b/java/doc/constant-values.html
@@ -185,160 +185,167 @@
 <td class="colLast"><code>128</code></td>
 </tr>
 <tr class="rowColor">
+<td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.FLAG_PROGRESSIVE">
+<!--   -->
+</a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
+<td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#FLAG_PROGRESSIVE">FLAG_PROGRESSIVE</a></code></td>
+<td class="colLast"><code>16384</code></td>
+</tr>
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.FLAG_STOPONWARNING">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#FLAG_STOPONWARNING">FLAG_STOPONWARNING</a></code></td>
 <td class="colLast"><code>8192</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.NUMCS">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#NUMCS">NUMCS</a></code></td>
 <td class="colLast"><code>5</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.NUMERR">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#NUMERR">NUMERR</a></code></td>
 <td class="colLast"><code>2</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.NUMPF">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#NUMPF">NUMPF</a></code></td>
 <td class="colLast"><code>12</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.NUMSAMP">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#NUMSAMP">NUMSAMP</a></code></td>
 <td class="colLast"><code>6</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_ABGR">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_ABGR">PF_ABGR</a></code></td>
 <td class="colLast"><code>9</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_ARGB">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_ARGB">PF_ARGB</a></code></td>
 <td class="colLast"><code>10</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_BGR">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_BGR">PF_BGR</a></code></td>
 <td class="colLast"><code>1</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_BGRA">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_BGRA">PF_BGRA</a></code></td>
 <td class="colLast"><code>8</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_BGRX">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_BGRX">PF_BGRX</a></code></td>
 <td class="colLast"><code>3</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_CMYK">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_CMYK">PF_CMYK</a></code></td>
 <td class="colLast"><code>11</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_GRAY">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_GRAY">PF_GRAY</a></code></td>
 <td class="colLast"><code>6</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_RGB">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_RGB">PF_RGB</a></code></td>
 <td class="colLast"><code>0</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_RGBA">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_RGBA">PF_RGBA</a></code></td>
 <td class="colLast"><code>7</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_RGBX">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_RGBX">PF_RGBX</a></code></td>
 <td class="colLast"><code>2</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_XBGR">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_XBGR">PF_XBGR</a></code></td>
 <td class="colLast"><code>4</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.PF_XRGB">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#PF_XRGB">PF_XRGB</a></code></td>
 <td class="colLast"><code>5</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.SAMP_411">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#SAMP_411">SAMP_411</a></code></td>
 <td class="colLast"><code>5</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.SAMP_420">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#SAMP_420">SAMP_420</a></code></td>
 <td class="colLast"><code>2</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.SAMP_422">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#SAMP_422">SAMP_422</a></code></td>
 <td class="colLast"><code>1</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.SAMP_440">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#SAMP_440">SAMP_440</a></code></td>
 <td class="colLast"><code>4</code></td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.SAMP_444">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
 <td><code><a href="org/libjpegturbo/turbojpeg/TJ.html#SAMP_444">SAMP_444</a></code></td>
 <td class="colLast"><code>0</code></td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><a name="org.libjpegturbo.turbojpeg.TJ.SAMP_GRAY">
 <!--   -->
 </a><code>public&nbsp;static&nbsp;final&nbsp;int</code></td>
--- a/java/doc/index-all.html
+++ b/java/doc/index-all.html
@@ -333,6 +333,11 @@
 <dd>
 <div class="block"><span class="strong">Deprecated.</span></div>
 </dd>
+<dt><span class="strong"><a href="./org/libjpegturbo/turbojpeg/TJ.html#FLAG_PROGRESSIVE">FLAG_PROGRESSIVE</a></span> - Static variable in class org.libjpegturbo.turbojpeg.<a href="./org/libjpegturbo/turbojpeg/TJ.html" title="class in org.libjpegturbo.turbojpeg">TJ</a></dt>
+<dd>
+<div class="block">Use progressive entropy coding in JPEG images generated by compression and
+ transform operations.</div>
+</dd>
 <dt><span class="strong"><a href="./org/libjpegturbo/turbojpeg/TJ.html#FLAG_STOPONWARNING">FLAG_STOPONWARNING</a></span> - Static variable in class org.libjpegturbo.turbojpeg.<a href="./org/libjpegturbo/turbojpeg/TJ.html" title="class in org.libjpegturbo.turbojpeg">TJ</a></dt>
 <dd>
 <div class="block">Immediately discontinue the current compression/decompression/transform
--- a/java/doc/org/libjpegturbo/turbojpeg/TJ.html
+++ b/java/doc/org/libjpegturbo/turbojpeg/TJ.html
@@ -210,138 +210,145 @@ extends java.lang.Object</pre>
 </tr>
 <tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
+<td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#FLAG_PROGRESSIVE">FLAG_PROGRESSIVE</a></strong></code>
+<div class="block">Use progressive entropy coding in JPEG images generated by compression and
+ transform operations.</div>
+</td>
+</tr>
+<tr class="altColor">
+<td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#FLAG_STOPONWARNING">FLAG_STOPONWARNING</a></strong></code>
 <div class="block">Immediately discontinue the current compression/decompression/transform
 operation if the underlying codec throws a warning (non-fatal error).</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#NUMCS">NUMCS</a></strong></code>
 <div class="block">The number of JPEG colorspaces</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#NUMERR">NUMERR</a></strong></code>
 <div class="block">The number of error codes</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#NUMPF">NUMPF</a></strong></code>
 <div class="block">The number of pixel formats</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#NUMSAMP">NUMSAMP</a></strong></code>
 <div class="block">The number of chrominance subsampling options</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_ABGR">PF_ABGR</a></strong></code>
 <div class="block">ABGR pixel format.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_ARGB">PF_ARGB</a></strong></code>
 <div class="block">ARGB pixel format.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_BGR">PF_BGR</a></strong></code>
 <div class="block">BGR pixel format.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_BGRA">PF_BGRA</a></strong></code>
 <div class="block">BGRA pixel format.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_BGRX">PF_BGRX</a></strong></code>
 <div class="block">BGRX pixel format.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_CMYK">PF_CMYK</a></strong></code>
 <div class="block">CMYK pixel format.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_GRAY">PF_GRAY</a></strong></code>
 <div class="block">Grayscale pixel format.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_RGB">PF_RGB</a></strong></code>
 <div class="block">RGB pixel format.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_RGBA">PF_RGBA</a></strong></code>
 <div class="block">RGBA pixel format.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_RGBX">PF_RGBX</a></strong></code>
 <div class="block">RGBX pixel format.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_XBGR">PF_XBGR</a></strong></code>
 <div class="block">XBGR pixel format.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#PF_XRGB">PF_XRGB</a></strong></code>
 <div class="block">XRGB pixel format.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#SAMP_411">SAMP_411</a></strong></code>
 <div class="block">4:1:1 chrominance subsampling.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#SAMP_420">SAMP_420</a></strong></code>
 <div class="block">4:2:0 chrominance subsampling.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#SAMP_422">SAMP_422</a></strong></code>
 <div class="block">4:2:2 chrominance subsampling.</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#SAMP_440">SAMP_440</a></strong></code>
 <div class="block">4:4:0 chrominance subsampling.</div>
 </td>
 </tr>
-<tr class="altColor">
+<tr class="rowColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#SAMP_444">SAMP_444</a></strong></code>
 <div class="block">4:4:4 chrominance subsampling (no chrominance subsampling).</div>
 </td>
 </tr>
-<tr class="rowColor">
+<tr class="altColor">
 <td class="colFirst"><code>static int</code></td>
 <td class="colLast"><code><strong><a href="../../../org/libjpegturbo/turbojpeg/TJ.html#SAMP_GRAY">SAMP_GRAY</a></strong></code>
 <div class="block">Grayscale.</div>
@@ -992,6 +999,20 @@ public static final&nbsp;int FLAG_FORCESSE3</pre>
 <dl><dt><span class="strong">See Also:</span></dt><dd><a href="../../../constant-values.html#org.libjpegturbo.turbojpeg.TJ.FLAG_STOPONWARNING">Constant Field Values</a></dd></dl>
 </li>
 </ul>
+<a name="FLAG_PROGRESSIVE">
+<!--   -->
+</a>
+<ul class="blockList">
+<li class="blockList">
+<h4>FLAG_PROGRESSIVE</h4>
+<pre>public static final&nbsp;int FLAG_PROGRESSIVE</pre>
+<div class="block">Use progressive entropy coding in JPEG images generated by compression and
+ transform operations.  Progressive entropy coding will generally improve
+ compression relative to baseline entropy coding (the default), but it will
+ reduce compression and decompression performance considerably.</div>
+<dl><dt><span class="strong">See Also:</span></dt><dd><a href="../../../constant-values.html#org.libjpegturbo.turbojpeg.TJ.FLAG_PROGRESSIVE">Constant Field Values</a></dd></dl>
+</li>
+</ul>
 <a name="NUMERR">
 <!--   -->
 </a>
--- a/java/org/libjpegturbo/turbojpeg/TJ.java
+++ b/java/org/libjpegturbo/turbojpeg/TJ.java
@@ -348,16 +348,16 @@ public final class TJ {
   * The uncompressed source/destination image is stored in bottom-up (Windows,
   * OpenGL) order, not top-down (X11) order.
   */
-  public static final int FLAG_BOTTOMUP     = 2;
+  public static final int FLAG_BOTTOMUP      = 2;

  @Deprecated
-  public static final int FLAG_FORCEMMX     = 8;
+  public static final int FLAG_FORCEMMX      = 8;
  @Deprecated
-  public static final int FLAG_FORCESSE     = 16;
+  public static final int FLAG_FORCESSE      = 16;
  @Deprecated
-  public static final int FLAG_FORCESSE2    = 32;
+  public static final int FLAG_FORCESSE2     = 32;
  @Deprecated
-  public static final int FLAG_FORCESSE3    = 128;
+  public static final int FLAG_FORCESSE3     = 128;

  /**
   * When decompressing an image that was compressed using chrominance
@@ -366,7 +366,7 @@ public final class TJ {
   * creates a smooth transition between neighboring chrominance components in
   * order to reduce upsampling artifacts in the decompressed image.
   */
-  public static final int FLAG_FASTUPSAMPLE = 256;
+  public static final int FLAG_FASTUPSAMPLE  = 256;
  /**
   * Use the fastest DCT/IDCT algorithm available in the underlying codec.  The
   * default if this flag is not specified is implementation-specific.  For
@@ -375,7 +375,7 @@ public final class TJ {
   * only a very slight effect on accuracy, but it uses the accurate algorithm
   * when decompressing, because this has been shown to have a larger effect.
   */
-  public static final int FLAG_FASTDCT      =  2048;
+  public static final int FLAG_FASTDCT       = 2048;
  /**
   * Use the most accurate DCT/IDCT algorithm available in the underlying
   * codec.  The default if this flag is not specified is
@@ -385,7 +385,7 @@ public final class TJ {
   * but it uses the accurate algorithm when decompressing, because this has
   * been shown to have a larger effect.
   */
-  public static final int FLAG_ACCURATEDCT  =  4096;
+  public static final int FLAG_ACCURATEDCT   = 4096;
  /**
   * Immediately discontinue the current compression/decompression/transform
   * operation if the underlying codec throws a warning (non-fatal error).  The
@@ -393,6 +393,13 @@ public final class TJ {
   * error is encountered.
   */
  public static final int FLAG_STOPONWARNING = 8192;
+  /**
+   * Use progressive entropy coding in JPEG images generated by compression and
+   * transform operations.  Progressive entropy coding will generally improve
+   * compression relative to baseline entropy coding (the default), but it will
+   * reduce compression and decompression performance considerably.
+   */
+  public static final int FLAG_PROGRESSIVE   = 16384;


  /**