diff --git a/src/pixels.cpp b/src/pixels.cpp
index 5e808c8..0a78381 100644
--- a/src/pixels.cpp
+++ b/src/pixels.cpp
@@ -16,17 +16,24 @@ static void write(std::ostream& os, FILE* in) {
     std::unique_ptr<tuple, void(*)(void*)> row1 {pnm_allocpamrow(&info), pm_freerow};
     std::unique_ptr<tuple, void(*)(void*)> row2 {pnm_allocpamrow(&info), pm_freerow};
     for (int y = 0; y < info.height; y += 2) {
+        tuple* t1 {row1.get()};
+        tuple* t2 {row2.get()};
         pnm_readpamrow(&info, row1.get());
-        pnm_readpamrow(&info, row2.get());
+        if (y < info.height - 1) {
+            pnm_readpamrow(&info, row2.get());
+        } else {
+            // fill second row with terminal background color
+            for (int col = 0; col < info.width; ++col) {
+                t2[col][0] = t2[col][1] = t2[col][2] = 0;
+            }
+        }
         for (int x = 0; x < info.width; ++x) {
             if (info.depth == 3) { // assume RGB, 1 byte per sample
-                tuple* t1 {row1.get()};
                 if (has_truecolor) {
                     os << sc::io::truecolorb(t1[x][0], t1[x][1], t1[x][2]);
                 } else {
                     os << sc::io::rgbb(t2p(t1[x][0]), t2p(t1[x][1]), t2p(t1[x][2]));
                 }
-                tuple* t2 {row2.get()};
                 if (has_truecolor) {
                     os << sc::io::truecolorf(t2[x][0], t2[x][1], t2[x][2]);
                 } else {