1 files changed, 64 insertions, 6 deletions

diff --git a/src/scanner.c b/src/scanner.c
index 8383f9f..f4eb08f 100644
--- a/src/scanner.c
+++ b/src/scanner.c
@@ -1160,7 +1160,7 @@ do_get_option (Scanner *scanner)
         }
         else if (strcmp (option->name, "three-pass") == 0) {
             set_bool_option (scanner->priv->handle, option, option_index, FALSE, NULL);
-        }                    
+        }
         else if (strcmp (option->name, "test-picture") == 0) {
             set_string_option (scanner->priv->handle, option, option_index, "Color pattern", NULL);
         }
@@ -1255,6 +1255,11 @@ do_get_parameters (Scanner *scanner)
     info->width = scanner->priv->parameters.pixels_per_line;
     info->height = scanner->priv->parameters.lines;
     info->depth = scanner->priv->parameters.depth;
+    /* Reduce bit depth if requested lower than received */
+    // FIXME: This a hack and only works on 8 bit gray to 2 bit gray
+    if (scanner->priv->parameters.depth == 8 && scanner->priv->parameters.format == SANE_FRAME_GRAY && job->depth == 2 && job->scan_mode == SCAN_MODE_GRAY)
+        info->depth = job->depth;
+    info->n_channels = scanner->priv->parameters.format == SANE_FRAME_GRAY ? 1 : 3;
     info->dpi = job->dpi; // FIXME: This is the requested DPI, not the actual DPI
     info->device = g_strdup (scanner->priv->current_device);
 
@@ -1308,10 +1313,13 @@ do_complete_page (Scanner *scanner)
 static void
 do_read (Scanner *scanner)
 {
+    ScanJob *job;
     SANE_Status status;
     SANE_Int n_to_read, n_read;
     gboolean full_read = FALSE;
 
+    job = (ScanJob *) scanner->priv->job_queue->data;
+
     /* Read as many bytes as we expect */
     n_to_read = scanner->priv->buffer_size - scanner->priv->n_used;
 
@@ -1351,19 +1359,19 @@ do_read (Scanner *scanner)
         line = g_malloc(sizeof(ScanLine));
         switch (scanner->priv->parameters.format) {
         case SANE_FRAME_GRAY:
-            line->format = LINE_GRAY;
+            line->channel = 0;
             break;
         case SANE_FRAME_RGB:
-            line->format = LINE_RGB;
+            line->channel = -1;
             break;
         case SANE_FRAME_RED:
-            line->format = LINE_RED;
+            line->channel = 0;
             break;
         case SANE_FRAME_GREEN:
-            line->format = LINE_GREEN;
+            line->channel = 1;
             break;
         case SANE_FRAME_BLUE:
-            line->format = LINE_BLUE;
+            line->channel = 2;
             break;
         }
         line->width = scanner->priv->parameters.pixels_per_line;
@@ -1387,6 +1395,56 @@ do_read (Scanner *scanner)
             scanner->priv->buffer[i] = line->data[i + (line->n_lines * line->data_length)];
             scanner->priv->n_used++;
         }
+
+        /* Reduce bit depth if requested lower than received */
+        // FIXME: This a hack and only works on 8 bit gray to 2 bit gray
+        if (scanner->priv->parameters.depth == 8 && scanner->priv->parameters.format == SANE_FRAME_GRAY &&
+            job->depth == 2 && job->scan_mode == SCAN_MODE_GRAY) {
+            gint block_shift = 6;
+            guchar block = 0;
+            guchar *write_ptr = line->data;
+
+            for (i = 0; i < line->n_lines; i++) {
+                guchar *in_line = line->data + i * line->data_length;
+                gint x;
+
+                for (x = 0; x < line->width; x++) {
+                     guchar *p = in_line + x;
+                     guchar sample;
+
+                     if (p[0] >= 192)
+                         sample = 3;
+                     else if (p[0] >= 128)
+                         sample = 2;
+                     else if (p[0] >= 64)
+                         sample = 1;
+                     else
+                         sample = 0;
+
+                     block |= sample << block_shift;
+                     if (block_shift == 0) {
+                         *write_ptr = block;
+                         write_ptr++;
+                         block = 0;
+                         block_shift = 6;
+                     }
+                     else {
+                         block_shift -= 2;
+                     }
+                }
+
+                /* Finish each line on a byte boundary */
+                if (block_shift != 6)  {
+                    *write_ptr = block;
+                    write_ptr++;
+                    block = 0;
+                    block_shift = 6;
+                }
+            }
+
+            line->data_length = (line->width * 2 + 7) / 8;
+        }
+
         emit_signal (scanner, GOT_LINE, line);
     }
 }