diff --git a/backend/genesys.cc b/backend/genesys.cc
index 50a275c75..3ab1a324b 100644
--- a/backend/genesys.cc
+++ b/backend/genesys.cc
@@ -3666,7 +3666,7 @@ static void genesys_read_ordered_data(Genesys_Device* dev, SANE_Byte* destinatio
     needs_reorder = 0;
 
   needs_ccd = dev->current_setup.max_shift > 0;
-  needs_shrink = dev->settings.pixels != src_pixels;
+  needs_shrink = dev->settings.requested_pixels != src_pixels;
   needs_reverse = depth == 1;
 
   DBG(DBG_info, "%s: using filters:%s%s%s%s\n", __func__,
@@ -3696,7 +3696,7 @@ static void genesys_read_ordered_data(Genesys_Device* dev, SANE_Byte* destinatio
 
   DBG(DBG_info, "%s: %lu lines left by output\n", __func__,
        ((dev->total_bytes_to_read - dev->total_bytes_read) * 8UL) /
-       (dev->settings.pixels * channels * depth));
+        (dev->settings.requested_pixels * channels * depth));
   DBG(DBG_info, "%s: %lu lines left by input\n", __func__,
        ((dev->read_bytes_left + dev->read_buffer.avail()) * 8UL) /
        (src_pixels * channels * depth));
@@ -3917,10 +3917,11 @@ Problems with the first approach:
       /* we are greedy. we work as much as possible */
       bytes = dst_buffer->size() - dst_buffer->avail();
 
-      if (dst_lines > (bytes * 8) / (dev->settings.pixels * channels * depth))
-	dst_lines = (bytes * 8) / (dev->settings.pixels * channels * depth);
+        if (dst_lines > (bytes * 8) / (dev->settings.requested_pixels * channels * depth)) {
+            dst_lines = (bytes * 8) / (dev->settings.requested_pixels * channels * depth);
+        }
 
-      bytes = (dst_lines * dev->settings.pixels * channels * depth) / 8;
+        bytes = (dst_lines * dev->settings.requested_pixels * channels * depth) / 8;
 
       work_buffer_dst = dst_buffer->get_write_pos(bytes);
 
@@ -3930,21 +3931,21 @@ Problems with the first approach:
 	{
 	  if (depth == 1)
             genesys_shrink_lines_1(work_buffer_src, work_buffer_dst, dst_lines, src_pixels,
-                                   dev->settings.pixels, channels);
+                                   dev->settings.requested_pixels, channels);
 	  else if (depth == 8)
             genesys_shrink_lines_8(work_buffer_src, work_buffer_dst, dst_lines, src_pixels,
-                                   dev->settings.pixels, channels);
+                                   dev->settings.requested_pixels, channels);
 	  else
             genesys_shrink_lines_16(work_buffer_src, work_buffer_dst, dst_lines, src_pixels,
-                                    dev->settings.pixels, channels);
+                                    dev->settings.requested_pixels, channels);
 
           /* we just consumed this many bytes*/
 	  bytes = (dst_lines * src_pixels * channels * depth) / 8;
             src_buffer->consume(bytes);
 
           /* we just created this many bytes*/
-	  bytes = (dst_lines * dev->settings.pixels * channels * depth) / 8;
-            dst_buffer->produce(bytes);
+        bytes = (dst_lines * dev->settings.requested_pixels * channels * depth) / 8;
+        dst_buffer->produce(bytes);
 	}
       src_buffer = dst_buffer;
     }
@@ -4118,6 +4119,7 @@ static void calc_parameters(Genesys_Scanner* s)
 
   s->dev->settings.lines = s->params.lines;
     s->dev->settings.pixels = pixels_per_line;
+    s->dev->settings.requested_pixels = pixels_per_line;
     s->params.pixels_per_line = pixels_per_line;
     s->params.bytes_per_line = bytes_per_line;
   s->dev->settings.tl_x = tl_x;
@@ -5113,7 +5115,7 @@ probe_genesys_devices (void)
    of Genesys_Calibration_Cache as is.
 */
 static const char* CALIBRATION_IDENT = "sane_genesys";
-static const int CALIBRATION_VERSION = 6;
+static const int CALIBRATION_VERSION = 7;
 
 bool read_calibration(std::istream& str, Genesys_Device::Calibration& calibration,
                       const std::string& path)
diff --git a/backend/genesys_gl124.cc b/backend/genesys_gl124.cc
index 9f6bf52f0..919d18361 100644
--- a/backend/genesys_gl124.cc
+++ b/backend/genesys_gl124.cc
@@ -1241,14 +1241,15 @@ static void gl124_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 
   dev->total_bytes_read = 0;
     if (session.params.depth == 1) {
-        dev->total_bytes_to_read = ((dev->settings.pixels * dev->settings.lines) / 8 +
-            (((dev->settings.pixels * dev->settings.lines) % 8) ? 1 : 0)) * session.params.channels;
+        dev->total_bytes_to_read = ((session.params.get_requested_pixels() * dev->settings.lines) / 8 +
+            (((session.params.get_requested_pixels() * dev->settings.lines) % 8) ? 1 : 0)) * session.params.channels;
     } else {
-        dev->total_bytes_to_read = dev->settings.pixels * dev->settings.lines *
+        dev->total_bytes_to_read = session.params.get_requested_pixels() * dev->settings.lines *
             session.params.channels * (session.params.depth / 8);
     }
 
-  DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
+    DBG(DBG_info, "%s: total bytes to send to frontend = %lu\n", __func__,
+        (u_long) dev->total_bytes_to_read);
 }
 
 static void
@@ -1280,6 +1281,7 @@ gl124_calculate_current_setup (Genesys_Device * dev, const Genesys_Sensor& senso
     session.params.startx = start;
     session.params.starty = 0; // not used
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
@@ -2012,6 +2014,7 @@ static void gl124_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
     session.params.startx = start;
     session.params.starty = move;
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
diff --git a/backend/genesys_gl646.cc b/backend/genesys_gl646.cc
index a66a338f7..535976050 100644
--- a/backend/genesys_gl646.cc
+++ b/backend/genesys_gl646.cc
@@ -816,6 +816,7 @@ static void gl646_setup_registers(Genesys_Device* dev,
    */
     dev->total_bytes_read = 0;
     if (session.params.depth == 1) {
+        // BUG: should use settings.requested_pixels
         dev->total_bytes_to_read = ((session.params.pixels * session.params.lines) / 8 +
             (((session.params.pixels * session.params.lines) % 8) ? 1 : 0)) * session.params.channels;
     } else {
diff --git a/backend/genesys_gl841.cc b/backend/genesys_gl841.cc
index b1ebd88a8..1be786944 100644
--- a/backend/genesys_gl841.cc
+++ b/backend/genesys_gl841.cc
@@ -2016,11 +2016,11 @@ dummy \ scanned lines
 
   dev->total_bytes_read = 0;
     if (session.params.depth == 1) {
-        dev->total_bytes_to_read = ((dev->settings.pixels * dev->settings.lines) / 8 +
-            (((dev->settings.pixels * dev->settings.lines)%8)?1:0)) *  session.params.channels;
+        dev->total_bytes_to_read = ((session.params.get_requested_pixels() * dev->settings.lines) / 8 +
+            (((session.params.get_requested_pixels() * dev->settings.lines)%8)?1:0)) *  session.params.channels;
     } else {
         dev->total_bytes_to_read =
-                dev->settings.pixels * dev->settings.lines * session.params.channels * (session.params.depth / 8);
+            session.params.get_requested_pixels() * dev->settings.lines * session.params.channels * (session.params.depth / 8);
     }
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
@@ -2059,6 +2059,7 @@ static void gl841_calculate_current_setup(Genesys_Device * dev, const Genesys_Se
     session.params.startx = start;
     session.params.starty = 0; // not used
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
@@ -3109,6 +3110,7 @@ static void gl841_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
     session.params.startx = start;
     session.params.starty = move;
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
diff --git a/backend/genesys_gl843.cc b/backend/genesys_gl843.cc
index a78aa5c0b..7fc81128f 100644
--- a/backend/genesys_gl843.cc
+++ b/backend/genesys_gl843.cc
@@ -1386,11 +1386,11 @@ static void gl843_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 
   dev->total_bytes_read = 0;
     if (session.params.depth == 1) {
-        dev->total_bytes_to_read = ((session.params.pixels * session.params.lines) / 8 +
-            (((session.params.pixels * session.params.lines) % 8) ? 1 : 0)) *
+        dev->total_bytes_to_read = ((session.params.get_requested_pixels() * session.params.lines) / 8 +
+            (((session.params.get_requested_pixels() * session.params.lines) % 8) ? 1 : 0)) *
                 session.params.channels;
     } else {
-        dev->total_bytes_to_read = session.params.pixels * session.params.lines *
+        dev->total_bytes_to_read = session.params.get_requested_pixels() * session.params.lines *
                 session.params.channels * (session.params.depth / 8);
     }
 
@@ -1440,6 +1440,7 @@ gl843_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
     session.params.startx = start; // not used
     session.params.starty = 0; // not used
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
@@ -2556,6 +2557,7 @@ static void gl843_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
     session.params.startx = start;
     session.params.starty = move;
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
diff --git a/backend/genesys_gl846.cc b/backend/genesys_gl846.cc
index c395659ee..686b25eaa 100644
--- a/backend/genesys_gl846.cc
+++ b/backend/genesys_gl846.cc
@@ -1121,11 +1121,11 @@ static void gl846_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 
   dev->total_bytes_read = 0;
     if (session.params.depth == 1) {
-        dev->total_bytes_to_read = ((session.params.pixels * session.params.lines) / 8 +
-                                    (((session.params.pixels * session.params.lines) % 8) ? 1 : 0)) *
+        dev->total_bytes_to_read = ((session.params.get_requested_pixels() * session.params.lines) / 8 +
+                                    (((session.params.get_requested_pixels() * session.params.lines) % 8) ? 1 : 0)) *
             session.params.channels;
     } else {
-        dev->total_bytes_to_read = session.params.pixels * session.params.lines * session.params.channels * (session.params.depth / 8);
+        dev->total_bytes_to_read = session.params.get_requested_pixels() * session.params.lines * session.params.channels * (session.params.depth / 8);
     }
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
@@ -1163,6 +1163,7 @@ gl846_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
     session.params.startx = start; // not used
     session.params.starty = 0; // not used
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
@@ -1781,6 +1782,7 @@ static void gl846_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
     session.params.startx = start;
     session.params.starty = move;
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
diff --git a/backend/genesys_gl847.cc b/backend/genesys_gl847.cc
index 35e313fca..e74eb7d35 100644
--- a/backend/genesys_gl847.cc
+++ b/backend/genesys_gl847.cc
@@ -1136,10 +1136,10 @@ static void gl847_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 
     dev->total_bytes_read = 0;
     if (session.params.depth == 1) {
-        dev->total_bytes_to_read = ((session.params.pixels * session.params.lines) / 8 +
-                                    (((session.params.pixels * session.params.lines) % 8) ? 1 : 0)) * session.params.channels;
+        dev->total_bytes_to_read = ((session.params.get_requested_pixels() * session.params.lines) / 8 +
+                                    (((session.params.get_requested_pixels() * session.params.lines) % 8) ? 1 : 0)) * session.params.channels;
     } else {
-        dev->total_bytes_to_read = session.params.pixels * session.params.lines * session.params.channels * (session.params.depth / 8);
+        dev->total_bytes_to_read = session.params.get_requested_pixels() * session.params.lines * session.params.channels * (session.params.depth / 8);
     }
 
   DBG(DBG_info, "%s: total bytes to send = %lu\n", __func__, (u_long) dev->total_bytes_to_read);
@@ -1177,6 +1177,7 @@ gl847_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
     session.params.startx = start; // not used
     session.params.starty = 0; // not used
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
@@ -1834,6 +1835,7 @@ static void gl847_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
     session.params.startx = start;
     session.params.starty = move;
     session.params.pixels = dev->settings.pixels;
+    session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;
     session.params.depth = dev->settings.get_depth();
     session.params.channels = dev->settings.get_channels();
diff --git a/backend/genesys_low.cc b/backend/genesys_low.cc
index cb43160b8..65c2f737a 100644
--- a/backend/genesys_low.cc
+++ b/backend/genesys_low.cc
@@ -1744,11 +1744,12 @@ void debug_dump(unsigned level, const Genesys_Settings& settings)
         "Resolution X/Y : %u / %u dpi\n"
         "Lines : %u\n"
         "Pixels per line : %u\n"
+        "Pixels per line (requested) : %u\n"
         "Depth : %u\n"
         "Start position X/Y : %.3f/%.3f\n"
         "Scan mode : %d\n\n",
         settings.xres, settings.yres,
-        settings.lines, settings.pixels, settings.depth,
+        settings.lines, settings.pixels, settings.requested_pixels, settings.depth,
         settings.tl_x, settings.tl_y,
         static_cast<unsigned>(settings.scan_mode));
 }
@@ -1759,6 +1760,7 @@ void debug_dump(unsigned level, const SetupParams& params)
         "Resolution X/Y : %u / %u dpi\n"
         "Lines : %u\n"
         "Pixels per line : %u\n"
+        "Pixels per line (requested) : %u\n"
         "Depth : %u\n"
         "Channels : %u\n"
         "Start position X/Y : %g / %g\n"
@@ -1766,7 +1768,7 @@ void debug_dump(unsigned level, const SetupParams& params)
         "Color filter : %d\n"
         "Flags : %x\n",
         params.xres, params.yres,
-        params.lines, params.pixels,
+        params.lines, params.pixels, params.requested_pixels,
         params.depth, params.channels,
         params.startx, params.starty,
         static_cast<unsigned>(params.scan_mode),
diff --git a/backend/genesys_settings.h b/backend/genesys_settings.h
index 6a391ecf2..c0e898307 100644
--- a/backend/genesys_settings.h
+++ b/backend/genesys_settings.h
@@ -66,6 +66,8 @@ struct Genesys_Settings
     unsigned int lines = 0;
     // number of pixels at scan resolution
     unsigned int pixels = 0;
+    // number of pixels expected by the frontend
+    unsigned requested_pixels = 0;
 
     // bit depth of the scan
     unsigned int depth = 0;
@@ -127,6 +129,10 @@ struct SetupParams {
     // the number of pixels in X direction. Note that each logical pixel may correspond to more
     // than one CCD pixel, see CKSEL and GenesysSensor::ccd_pixels_per_system_pixel()
     unsigned pixels = NOT_SET;
+
+    // the number of pixels in the X direction as requested by the frontend.
+    unsigned requested_pixels = 0;
+
     // the number of pixels in Y direction
     unsigned lines = NOT_SET;
     // the depth of the scan in bits. Allowed are 1, 8, 16
@@ -142,6 +148,14 @@ struct SetupParams {
 
     unsigned flags = NOT_SET;
 
+    unsigned get_requested_pixels() const
+    {
+        if (requested_pixels != 0) {
+            return requested_pixels;
+        }
+        return pixels;
+    }
+
     void assert_valid() const
     {
         if (xres == NOT_SET || yres == NOT_SET || startx < 0 || starty < 0 ||
@@ -162,6 +176,7 @@ struct SetupParams {
             startx == other.startx &&
             starty == other.starty &&
             pixels == other.pixels &&
+            requested_pixels == other.requested_pixels &&
             lines == other.lines &&
             depth == other.depth &&
             channels == other.channels &&
@@ -180,6 +195,7 @@ void serialize(Stream& str, SetupParams& x)
     serialize(str, x.startx);
     serialize(str, x.starty);
     serialize(str, x.pixels);
+    serialize(str, x.requested_pixels);
     serialize(str, x.lines);
     serialize(str, x.depth);
     serialize(str, x.channels);