Merge lp:~victor-mireyev/simple-scan/484616 into lp:~simple-scan-team/simple-scan/trunk

[Victor Mireyev]

Save DPI with JPEG

[Robert Ancell (robert-ancell)]

Can you remove the JpegWriter class back to how it was? It doesn't seem to add anything and it makes it harder to review.

Please correct the whitespace before the '(' in the use of functions.

Other than that, looks good.

review: Needs Fixing

[Robert Ancell (robert-ancell)]

Is this an enum? Can you put the enum values into the .vapi if so?
+ info.density_unit = 1;

[Victor Mireyev (greymouse2005)]

As you can see, there are three important changes:
1) optional density parameter is added
2) n_written parameter is removed as it's trivially obtained via jpeg_data.length
3) Quality and density code is added
92+ info.set_quality (90);
93 + if (density != null)
94 + {
95 + info.density_unit = 1;
96 + info.X_density = (uint16) density;
97 + info.Y_density = (uint16) density;
98 + }

There are two reason for existance of JpegWriter class.

1) JPEG compression code doesn't use any nonstatic methods or properties of the Book class.
2) As JPEG compression code is used in both Book and Page classes, it shouldn't be duplicated.

Do you propose make compress_jpeg method static?

[lp:~victor-mireyev/simple-scan/484616]

598. By Victor Mireyev on 2013-05-30

Remove JpegWriter. New DensityUnit enumeration

Unmerged revisions

598. By Victor Mireyev on 2013-05-30

Remove JpegWriter. New DensityUnit enumeration

597. By Victor Mireyev on 2012-09-03

Save DPI with JPEG.

=== modified file 'src/book.vala'
--- src/book.vala	2013-05-27 22:18:27 +0000
+++ src/book.vala	2013-05-30 21:12:26 +0000
@@ -9,6 +9,13 @@
  * license.
  */
 
+enum DensityUnit
+{
+    NO_UNITS,
+    PIXELS_PER_INCH,
+    PIXELS_PER_CENTIMETER
+}
+
 public class Book
 {
     private List<Page> pages;
@@ -183,7 +190,7 @@
     private static bool jpeg_empty_cb (JPEG.Compress info) { return true; }
     private static void jpeg_term_cb (JPEG.Compress info) {}
 
-    private uint8[] compress_jpeg (Gdk.Pixbuf image, out size_t n_written)
+    public static uint8[] compress_jpeg (Gdk.Pixbuf image, int? density = null)
     {
         var info = JPEG.Compress ();
         var jerr = JPEG.ErrorManager ();
@@ -198,6 +205,15 @@
         info.in_color_space = JPEG.ColorSpace.RGB; /* TODO: JCS_GRAYSCALE? */
         info.set_defaults ();
 
+        info.set_quality (90);        
+        if (density != null)
+        {
+            uint8 unit = DensityUnit.PIXELS_PER_INCH;
+            info.density_unit = unit;
+            info.X_density = (uint16) density;
+            info.Y_density = (uint16) density;
+        }
+
         var max_length = info.image_width * info.image_height * info.input_components;
         var data = new uint8[max_length];
         dest_mgr.next_output_byte = data;
@@ -216,8 +232,8 @@
             info.write_scanlines (row, 1);
         }
         info.finish_compress ();
-        n_written = max_length - dest_mgr.free_in_buffer;
-        data.resize ((int) n_written);
+        int n_written = max_length - dest_mgr.free_in_buffer;
+        data.resize (n_written);
 
         return data;
     }
@@ -414,9 +430,8 @@
                 /* Try if JPEG compression is better */
                 if (depth > 1)
                 {
-                    size_t jpeg_length;
-                    var jpeg_data = compress_jpeg (image, out jpeg_length);
-                    if (jpeg_length < compressed_data.length)
+                    var jpeg_data = compress_jpeg (image);
+                    if (jpeg_data.length < compressed_data.length)
                     {
                         filter = "DCTDecode";
                         data = jpeg_data;

=== modified file 'src/jpeglib.vapi'
--- src/jpeglib.vapi	2011-06-12 04:55:11 +0000
+++ src/jpeglib.vapi	2013-05-30 21:12:26 +0000
@@ -22,6 +22,11 @@
         public int input_components;
         public ColorSpace in_color_space;
         public ErrorManager* err;
+        
+        public uint8 density_unit;
+        public uint16 X_density;
+        public uint16 Y_density;
+        public void set_quality (int quality, bool force_baseline = true);
 
         public void create_compress ();
         public void set_defaults ();

=== modified file 'src/page.vala'
--- src/page.vala	2013-05-19 21:55:27 +0000
+++ src/page.vala	2013-05-30 21:12:26 +0000
@@ -704,10 +704,8 @@
 
         if (strcmp (type, "jpeg") == 0)
         {
-            /* ICC profile is awaiting review in gtk2+ bugzilla */
-            string[] keys = { "quality", /* "icc-profile", */ null };
-            string[] values = { "90", /* icc_profile_data, */ null };
-            writer.save (image, "jpeg", keys, values);
+            var data = Book.compress_jpeg (image, this.get_dpi ());
+            stream.write_all (data, null, null);
         }
         else if (strcmp (type, "png") == 0)
         {