diff --git a/bitblt.c b/bitblt.c
index 8c3339a..a12a9e1 100644
--- a/bitblt.c
+++ b/bitblt.c
@@ -4,7 +4,7 @@
  *      will be compressed using ITU-T T.6 (G4) fax encoding.
  *
  * bitblt routines
- * $Id: bitblt.c,v 1.11 2003/02/19 02:14:44 eric Exp $
+ * $Id: bitblt.c,v 1.12 2003/02/20 04:11:06 eric Exp $
  * Copyright 2001, 2002, 2003 Eric Smith <eric@brouhaha.com>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -726,6 +726,79 @@ void rot_270 (Bitmap *src)  /* transpose + flip_v */
 }
 
 
-void bitblt_init (void)
+int32_t get_row_run_lengths (Bitmap *src,
+			     int32_t y,
+			     int32_t min_x, int32_t max_x,
+			     int32_t max_runs,
+			     uint32_t *run_length)
 {
+  uint8_t *byte_ptr;
+  uint8_t byte;
+  int bit_pos;
+
+  uint32_t byte_cnt;
+  int last_bits;
+  bool last_flag = 0;
+
+  uint8_t pol = 0x00;  /* 0x00 = counting zeros (white),
+			  0xff = counting ones (black) */
+
+  uint32_t rl;
+  int32_t i = 0;
+
+  /* adjust coordinate system */
+  y -= src->rect.min.y;
+  min_x -= src->rect.min.x;
+  max_x -= src->rect.min.x;
+
+  byte_ptr = (uint8_t *) (src->bits + y * src->row_words);
+  byte_cnt = (max_x / 8) + 1 - (min_x / 8);
+  last_bits = max_x % 8;
+
+  rl = 0;
+  pol = 0x00;  /* initially count white pixels */
+
+  byte_ptr += min_x / 8;
+  bit_pos = min_x % 8;
+  byte = *(byte_ptr++);
+
+  /* is the first byte also the last? */
+  if (--byte_cnt == 0)
+    {
+      byte <<= (7 - last_bits);	  /* last byte may be partial */
+      bit_pos += (7 - last_bits);
+      last_flag = 1;
+    }
+
+  for (;;)
+    {
+      int b2 = rle_tab [bit_pos] [pol ^ byte];
+      rl += b2;
+      bit_pos += b2;
+      if (bit_pos == 8)
+	{
+	  if (last_flag)
+	    {
+	      if (rl)
+		run_length [i++] = rl;
+	      return (i);
+	    }
+	  bit_pos = 0;
+	  byte = *(byte_ptr++);
+	  if (--byte_cnt == 0)
+	    {
+	      byte <<= (7 - last_bits);	  /* last byte may be partial */
+	      bit_pos += (7 - last_bits);
+	      last_flag = 1;
+	    }
+	}
+      else
+	{
+	  run_length [i++] = rl;
+	  if (i == max_runs)
+	    return (-i);
+	  rl = 0;
+	  pol ^= 0xff;
+	}
+    }
 }
diff --git a/bitblt.h b/bitblt.h
index 8c39ab3..4e629e5 100644
--- a/bitblt.h
+++ b/bitblt.h
@@ -4,7 +4,7 @@
  *      will be compressed using ITU-T T.6 (G4) fax encoding.
  *
  * bitblt routines
- * $Id: bitblt.h,v 1.10 2003/02/19 02:14:44 eric Exp $
+ * $Id: bitblt.h,v 1.11 2003/02/20 04:11:06 eric Exp $
  * Copyright 2001, 2002, 2003 Eric Smith <eric@brouhaha.com>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -98,3 +98,25 @@ void rot_270 (Bitmap *src);  /* transpose + flip_v */
 
 
 void reverse_bits (uint8_t *p, int byte_count);
+
+
+/*
+ * get_row_run_lengths counts the runs of 0 and 1 bits in row
+ * y of a bitmap, from min_x through max_x inclusive.  The run lengths
+ * will be stored in the run_length array.  The first entry will be
+ * the length of a zero run (which length may be zero, if the first
+ * bit is a one).  The next entry will the be the length of a run of
+ * ones, and they will alternate from there, with even entries representing
+ * runs of zeros, and odd entries representing runs of ones.
+ *
+ * max_runs should be set to the maximum number of run lengths that
+ * can be stored in the run_length array.
+ *
+ * Returns the actual number of runs counted, or -max_runs if there
+ * was not enough room in the array.
+ */
+int32_t get_row_run_lengths (Bitmap *src,
+			     int32_t y,
+			     int32_t min_x, int32_t max_x,
+			     int32_t max_runs,
+			     uint32_t *run_length);