diff --git a/src/lib/direct.c b/src/lib/direct.c
index c48f76651..e8de5e3b9 100644
--- a/src/lib/direct.c
+++ b/src/lib/direct.c
@@ -532,9 +532,13 @@ static ncdirectv*
 ncdirect_render_visual(ncdirect* n, ncvisual* ncv, ncblitter_e blitfxn,
                        ncscale_e scale, int ymax, int xmax,
                        uint32_t transcolor){
+  if(ymax < 0 || xmax < 0){
+    fprintf(stderr, "Invalid render geometry %d/%d\n", ymax, xmax);
+    return NULL;
+  }
   int dimy = ymax > 0 ? ymax : (ncdirect_dim_y(n) - 1);
   int dimx = xmax > 0 ? xmax : ncdirect_dim_x(n);
-//fprintf(stderr, "OUR DATA: %p rows/cols: %d/%d outsize: %d/%d %d\n", ncv->data, ncv->pixy, ncv->pixx, dimy, dimx, ymax);
+//fprintf(stderr, "OUR DATA: %p rows/cols: %d/%d outsize: %d/%d %d/%d\n", ncv->data, ncv->pixy, ncv->pixx, dimy, dimx, ymax, xmax);
 //fprintf(stderr, "render %d/%d to scaling: %d\n", ncv->pixy, ncv->pixx, scale);
   const struct blitset* bset = rgba_blitter_low(&n->tcache, scale, true, blitfxn);
   if(!bset){
@@ -572,6 +576,7 @@ ncdirect_render_visual(ncdirect* n, ncvisual* ncv, ncblitter_e blitfxn,
       disprows = outy;
     }
   }
+//fprintf(stderr, "max: %d/%d out: %d/%d\n", ymax, xmax, outy, dispcols);
 //fprintf(stderr, "render: %d/%d stride %u %p\n", ncv->pixy, ncv->pixx, ncv->pixytride, ncv->data);
   ncplane_options nopts = {
     .y = 0,
@@ -587,6 +592,12 @@ ncdirect_render_visual(ncdirect* n, ncvisual* ncv, ncblitter_e blitfxn,
     nopts.rows = outy / n->tcache.cellpixy + !!(outy % n->tcache.cellpixy);
     nopts.cols = dispcols / n->tcache.cellpixx + !!(dispcols % n->tcache.cellpixx);
   }
+  if(ymax && nopts.rows > ymax){
+    nopts.rows = ymax;
+  }
+  if(xmax && nopts.cols > xmax){
+    nopts.cols = xmax;
+  }
   struct ncplane* ncdv = ncplane_new_internal(NULL, NULL, &nopts);
   if(!ncdv){
     return NULL;
@@ -624,7 +635,7 @@ ncdirectv* ncdirect_render_frame(ncdirect* n, const char* file,
 
 int ncdirect_render_image(ncdirect* n, const char* file, ncalign_e align,
                           ncblitter_e blitfxn, ncscale_e scale){
-  ncdirectv* faken = ncdirect_render_frame(n, file, blitfxn, scale, -1, -1);
+  ncdirectv* faken = ncdirect_render_frame(n, file, blitfxn, scale, 0, 0);
   if(!faken){
     return -1;
   }
diff --git a/src/lib/internal.h b/src/lib/internal.h
index 3b5f7c8b2..7460c96fd 100644
--- a/src/lib/internal.h
+++ b/src/lib/internal.h
@@ -618,6 +618,8 @@ typedef struct blitterargs {
   // consumed there, and blitters ought always work with the scaled output.
   int begy;            // upper left start within visual
   int begx;
+  int leny;            // number of source pixels to use
+  int lenx;
   uint32_t transcolor; // if non-zero, treat the lower 24 bits as a transparent color
   union { // cell vs pixel-specific arguments
     struct {
diff --git a/src/poc/vizdirect.c b/src/poc/vizdirect.c
index 537821799..295dd9368 100644
--- a/src/poc/vizdirect.c
+++ b/src/poc/vizdirect.c
@@ -2,6 +2,42 @@
 #include <unistd.h>
 #include <notcurses/direct.h>
 
+// print progressive partial subsets of the image
+static int
+partial_image(struct ncdirect* n, const char* file){
+  ncdirectf* nf = ncdirectf_from_file(n, file);
+  if(nf == NULL){
+    return -1;
+  }
+  // get the number of pixels
+  ncvgeom geom;
+  ncblitter_e blit = NCBLIT_1x1;
+  ncdirectf_geom(n, nf, &blit, NCSCALE_NONE, 0, 0, &geom);
+  if(geom.cdimy <= 0){
+    fprintf(stderr, "no cell dim information\n");
+    ncdirectf_free(nf);
+    return -1;
+  }
+  for(int y = geom.pixy ; y > 0 ; y -= 5){
+    int rows = y;
+    for(int x = geom.pixx ; x > 0 ; x -= 5){
+      int cols = x;
+      ncdirectv* v;
+      printf("Size: %dx%d\n", cols, rows);
+      if((v = ncdirectf_render(n, nf, blit, NCSCALE_NONE, rows, cols)) == NULL){
+        ncdirectf_free(nf);
+        return -1;
+      }
+      if(ncdirect_raster_frame(n, v, NCALIGN_CENTER)){
+        ncdirectf_free(nf);
+        return -1;
+      }
+    }
+  }
+  ncdirectf_free(nf);
+  return 0;
+}
+
 // can we leave what was already on the screen there? (narrator: it seems not)
 int main(void){
   if(!setlocale(LC_ALL, "")){