diff --git a/src/bin/jp2/convert.c b/src/bin/jp2/convert.c
index a540128f..730ab909 100644
--- a/src/bin/jp2/convert.c
+++ b/src/bin/jp2/convert.c
@@ -1890,6 +1890,21 @@ opj_image_t* pnmtoimage(const char *filename, opj_cparameters_t *parameters)
     return image;
 }/* pnmtoimage() */
 
+static int are_comps_similar(opj_image_t * image)
+{
+    unsigned int i;
+    for (i = 1; i < image->numcomps; i++) {
+        if (image->comps[0].dx != image->comps[i].dx ||
+                image->comps[0].dy != image->comps[i].dy ||
+                image->comps[0].prec != image->comps[i].prec ||
+                image->comps[0].sgnd != image->comps[i].sgnd) {
+            return OPJ_FALSE;
+        }
+    }
+    return OPJ_TRUE;
+}
+
+
 int imagetopnm(opj_image_t * image, const char *outfile, int force_split)
 {
     int *red, *green, *blue, *alpha;
@@ -1926,15 +1941,7 @@ int imagetopnm(opj_image_t * image, const char *outfile, int force_split)
     }
 
     if ((force_split == 0) &&
-            (ncomp == 2 /* GRAYA */
-             || (ncomp > 2 /* RGB, RGBA */
-                 && image->comps[0].dx == image->comps[1].dx
-                 && image->comps[1].dx == image->comps[2].dx
-                 && image->comps[0].dy == image->comps[1].dy
-                 && image->comps[1].dy == image->comps[2].dy
-                 && image->comps[0].prec == image->comps[1].prec
-                 && image->comps[1].prec == image->comps[2].prec
-                ))) {
+            are_comps_similar(image)) {
         fdest = fopen(outfile, "wb");
 
         if (!fdest) {