Require libjpeg for reading and writing tiff files

* Also fix colorcontent_reg to work with different jpeg libraries * Fixes Issue #719 and Issue #720, reported by @johnsonea. * Documentation change for Issue #717, reported by @kloczek.
DanBloomberg · Nov 1, 2023 · 21d901e · 21d901e
1 parent 6d2c1c5
commit 21d901e
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Showing 5 changed files with 25 additions and 19 deletions.
diff --git a/README.html b/README.html
@@ -242,7 +242,8 @@ <h2> <A NAME="BUILDING">
                              This works even if you build in a different
                              place from the distribution. The -j parameter
                              should not exceed half the number of cores.
-                             If the test fails, just run with 'make check']
+                     NOTE: If the test fails, it's likely due to a race
+                           condition.  Rerun with 'make check']
 
        Configure supports installing in a local directory (e.g., one that
        doesn't require root access).  For example, to install in $HOME/local,
@@ -968,7 +969,9 @@ <h2> <A NAME="CONTENTS">
       text and line art images, but it does quite poorly for halftones.
       It has good and stable support by Leffler's open source library,
       which is clean and small.  Tiff also supports multipage
-      images through a directory structure.  See tiffio.c
+      images through a directory structure.  Note: because jpeg is
+      a supported tiff compression mode, leptonica requires linking
+      both libtiff and libjpeg to read and write tiff.  See tiffio.c
 
     - BMP has (until recently) had no compression.  It is a simple
       format with colormaps that requires no external libraries.

diff --git a/prog/colorcontent_reg.c b/prog/colorcontent_reg.c
@@ -79,10 +79,12 @@ L_REGPARAMS  *rp;
     pixDestroy(&pix2);
     pixDestroy(&pix3);
 
-        /* Do a simple color quantization with sigbits = 3 */
+        /* Do a simple color quantization with sigbits = 3.
+         * Roundoff from different jpeg decompression algorithms can
+         * result in differing numbers of colors by a few percent.  */
     pix1 = pixRead("wyom.jpg");
     pixNumColors(pix1, 1, &ncolors);  /* >255, so should give 0 */
-    regTestCompareValues(rp, ncolors, 132165, 0.0);  /* 4 */
+    regTestCompareValues(rp, ncolors, 132165, 10000.0);  /* 4 */
     pix2 = pixSimpleColorQuantize(pix1, 3, 3, 20);
     pixDisplayWithTitle(pix2, 1000, 0, NULL, rp->display);
     regTestWritePixAndCheck(rp, pix2, IFF_PNG);  /* 5 */

diff --git a/src/readfile.c b/src/readfile.c
@@ -1358,7 +1358,7 @@ PIXCMAP   *cmap;
 #endif  /* HAVE_LIBPNG */
 
         /* ----------------------- TIFF -------------------------- */
-#if HAVE_LIBTIFF
+#if HAVE_LIBTIFF && HAVE_LIBJPEG
         /* TIFF works for 1, 2, 4, 8, 16 and 32 bpp images.
          * Because 8 bpp tiff always writes 256 entry colormaps, the
          * colormap sizes may be different for 8 bpp images with
@@ -1478,7 +1478,7 @@ PIXCMAP   *cmap;
         }
         pixDestroy(&pix1);
     }
-#endif  /* HAVE_LIBTIFF */
+#endif  /* HAVE_LIBTIFF && HAVE_LIBJPEG */
 
         /* ----------------------- PNM -------------------------- */
 

diff --git a/src/tiffio.c b/src/tiffio.c
@@ -103,7 +103,8 @@
  *            tiff library, such as G3, G4, RLE and LZW.
  *          * The exception is the old-style jpeg tiff format (OJPEG), which
  *            is not supported.
- *          * We support only one format, ZIP, that uses an external library.
+ *          * We support two formats requiring external libraries: ZIP and JPEG
+ *            Both libz and libjpeg are required.
  *          * At present we do not support WEBP in tiff, which uses
  *            libwebp and was added in tifflib 4.1.0 in 2019.
  *  Note 3: On Windows with 2 bpp or 4 bpp images, the bytes in the
@@ -130,9 +131,9 @@
 #include <fcntl.h>
 #include "allheaders.h"
 
-/* --------------------------------------------*/
-#if  HAVE_LIBTIFF   /* defined in environ.h */
-/* --------------------------------------------*/
+/* ---------------------------------------------------------*/
+#if  HAVE_LIBTIFF && HAVE_LIBJPEG   /* defined in environ.h */
+/* ---------------------------------------------------------*/
 
 #include "tiff.h"
 #include "tiffio.h"
@@ -2877,6 +2878,6 @@ TIFF    *tif;
     return ret;
 }
 
-/* --------------------------------------------*/
-#endif  /* HAVE_LIBTIFF */
-/* --------------------------------------------*/
+/* ---------------------------------------*/
+#endif  /* HAVE_LIBTIFF && HAVE_LIBJPEG   */
+/* ---------------------------------------*/
diff --git a/src/tiffiostub.c b/src/tiffiostub.c
@@ -38,9 +38,9 @@
 
 #include "allheaders.h"
 
-/* --------------------------------------------*/
-#if  !HAVE_LIBTIFF   /* defined in environ.h */
-/* --------------------------------------------*/
+/* -----------------------------------------------------------*/
+#if  !HAVE_LIBTIFF || !HAVE_LIBJPEG  /* defined in environ.h  */
+/* -----------------------------------------------------------*/
 
 PIX * pixReadTiff(const char *filename, l_int32 n)
 {
@@ -233,6 +233,6 @@ l_ok pixWriteMemTiffCustom(l_uint8 **pdata, size_t *psize, PIX *pix,
     return ERROR_INT("function not present", __func__, 1);
 }
 
-/* --------------------------------------------*/
-#endif  /* !HAVE_LIBTIFF */
-/* --------------------------------------------*/
+/* -----------------------------------------*/
+#endif  /* !HAVE_LIBTIFF || !HAVE_LIBJPEG   */
+/* -----------------------------------------*/