From 4735d941d9b11bcca7cd55fec5519f440b2c7e64 Mon Sep 17 00:00:00 2001
From: Matthew Sheby <44249925+msheby@users.noreply.github.com>
Date: Wed, 20 Oct 2021 15:29:04 -0700
Subject: [PATCH] enable decimation of input TIF

---
 src/bin/jp2/converttif.c   |  4 ++++
 src/bin/jp2/opj_compress.c | 19 ++++++++++++++++++-
 src/lib/openjp2/openjpeg.c |  1 +
 src/lib/openjp2/openjpeg.h |  2 ++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/bin/jp2/converttif.c b/src/bin/jp2/converttif.c
index efd5a4e7..c349f520 100644
--- a/src/bin/jp2/converttif.c
+++ b/src/bin/jp2/converttif.c
@@ -1507,6 +1507,10 @@ opj_image_t* tiftoimage(const char *filename, opj_cparameters_t *parameters)
             scale_component(&(image->comps[j]), 12);
         }
 
+    } else if ((parameters->target_bitdepth > 0) && (parameters->target_bitdepth != tiBps)) {
+        for (j = 0; j < numcomps; ++j) {
+            scale_component(&(image->comps[j]), parameters->target_bitdepth);
+        }
     }
     return image;
 
diff --git a/src/bin/jp2/opj_compress.c b/src/bin/jp2/opj_compress.c
index e488abcd..2472f6d8 100644
--- a/src/bin/jp2/opj_compress.c
+++ b/src/bin/jp2/opj_compress.c
@@ -186,6 +186,10 @@ static void encode_help_display(void)
     fprintf(stdout,
             "    It corresponds to the number of DWT decompositions +1. \n");
     fprintf(stdout, "    Default: 6.\n");
+    fprintf(stdout, "-X <target bitdepth>\n");
+    fprintf(stdout, "    Target bitdepth.\n");
+    fprintf(stdout, "    Number of bits per component to use from input image\n");
+    fprintf(stdout, "    if all bits are unwanted. \n");
     fprintf(stdout, "-b <cblk width>,<cblk height>\n");
     fprintf(stdout,
             "    Code-block size. The dimension must respect the constraint \n");
@@ -623,7 +627,7 @@ static int parse_cmdline_encoder(int argc, char **argv,
     };
 
     /* parse the command line */
-    const char optlist[] = "i:o:r:q:n:b:c:t:p:s:SEM:x:R:d:T:If:P:C:F:u:JY:"
+    const char optlist[] = "i:o:r:q:n:b:c:t:p:s:SEM:x:R:d:T:If:P:C:F:u:JY:X:"
 #ifdef USE_JPWL
                            "W:"
 #endif /* USE_JPWL */
@@ -908,6 +912,19 @@ static int parse_cmdline_encoder(int argc, char **argv,
         }
         break;
 
+        /* ----------------------------------------------------- */
+        case 'X': {         /* target bitdepth */
+            int target_bitdepth = 0;
+            char *s = opj_optarg;
+            sscanf(s, "%d", &target_bitdepth);
+            if (target_bitdepth <= 0) {
+              fprintf(stderr, "Target bitdepth must be at least 1 bit.\n");
+              return 1;
+            }
+            parameters->target_bitdepth = target_bitdepth;
+        }
+        break;
+
         /* ----------------------------------------------------- */
 
         case 'n': {         /* resolution */
diff --git a/src/lib/openjp2/openjpeg.c b/src/lib/openjp2/openjpeg.c
index 0c5f2d5f..f0db4670 100644
--- a/src/lib/openjp2/openjpeg.c
+++ b/src/lib/openjp2/openjpeg.c
@@ -756,6 +756,7 @@ void OPJ_CALLCONV opj_set_default_encoder_parameters(opj_cparameters_t
         parameters->tp_on = 0;
         parameters->decod_format = -1;
         parameters->cod_format = -1;
+        parameters->target_bitdepth = -1;
         parameters->tcp_rates[0] = 0;
         parameters->tcp_numlayers = 0;
         parameters->cp_disto_alloc = 0;
diff --git a/src/lib/openjp2/openjpeg.h b/src/lib/openjp2/openjpeg.h
index 8829963f..21bc48e7 100644
--- a/src/lib/openjp2/openjpeg.h
+++ b/src/lib/openjp2/openjpeg.h
@@ -465,6 +465,8 @@ typedef struct opj_cparameters {
     int decod_format;
     /** output file format 0: J2K, 1: JP2, 2: JPT */
     int cod_format;
+    /** desired bitdepth from input file */
+    int target_bitdepth;
     /*@}*/
 
     /* UniPG>> */ /* NOT YET USED IN THE V2 VERSION OF OPENJPEG */