1 files changed, 30 insertions, 0 deletions
diff --git a/sys/imio/imnote.x b/sys/imio/imnote.x
new file mode 100644
index 00000000..09547043
--- /dev/null
+++ b/sys/imio/imnote.x
@@ -0,0 +1,30 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<imhdr.h>
+include	<imio.h>
+
+# IMNOTE -- Given the coordinates of a pixel, return the character offset
+# of that pixel in the pixel storage file.
+
+long procedure imnote (im, v)
+
+pointer	im			# image descriptor
+long	v[IM_MAXDIM]		# physical coords of pixel
+
+int	sz_pixel, i
+long	pixel_index, dim_offset, char_offset0
+include	<szpixtype.inc>
+
+begin
+	sz_pixel = pix_size[IM_PIXTYPE(im)]
+	pixel_index = v[1]
+	dim_offset = 1
+
+	do i = 2, IM_NPHYSDIM(im) {
+	    dim_offset = dim_offset * IM_PHYSLEN(im,i-1)
+	    pixel_index = pixel_index + dim_offset * (v[i] - 1)
+	}
+
+	char_offset0 = (pixel_index-1) * sz_pixel
+	return (IM_PIXOFF(im) + char_offset0)
+end