Merge pull request #730 from videan42/jpeg2k-16bit-clean

16-bit monochrome support for JPEG2000

PIL/Jpeg2KImagePlugin.py

@@ -40,7 +40,10 @@ def _parse_codestream(fp):
 
     size = (xsiz - xosiz, ysiz - yosiz)
     if csiz == 1:
-        mode = 'L'
+        if (yrsiz[0] & 0x7f) > 8:
+            mode = 'I;16'
+        else:
+            mode = 'L'
     elif csiz == 2:
         mode = 'LA'
     elif csiz == 3:
@@ -78,6 +81,7 @@ def _parse_jp2_header(fp):
 
     size = None
     mode = None
+    bpc = None
 
     hio = io.BytesIO(header)
     while True:
@@ -95,7 +99,9 @@ def _parse_jp2_header(fp):
                 = struct.unpack('>IIHBBBB', content)
             size = (width, height)
             if unkc:
-                if nc == 1:
+                if nc == 1 and (bpc & 0x7f) > 8:
+                    mode = 'I;16'
+                elif nc == 1:
                     mode = 'L'
                 elif nc == 2:
                     mode = 'LA'
@@ -109,13 +115,19 @@ def _parse_jp2_header(fp):
             if meth == 1:
                 cs = struct.unpack('>I', content[3:7])[0]
                 if cs == 16:   # sRGB
-                    if nc == 3:
+                    if nc == 1 and (bpc & 0x7f) > 8:
+                        mode = 'I;16'
+                    elif nc == 1:
+                        mode = 'L'
+                    elif nc == 3:
                         mode = 'RGB'
                     elif nc == 4:
                         mode = 'RGBA'
                     break
                 elif cs == 17:  # grayscale
-                    if nc == 1:
+                    if nc == 1 and (bpc & 0x7f) > 8:
+                        mode = 'I;16'
+                    elif nc == 1:
                         mode = 'L'
                     elif nc == 2:
                         mode = 'LA'
@@ -129,10 +141,10 @@ def _parse_jp2_header(fp):
 
     return (size, mode)
 
-
 ##
 # Image plugin for JPEG2000 images.
 
+
 class Jpeg2KImageFile(ImageFile.ImageFile):
     format = "JPEG2000"
     format_description = "JPEG 2000 (ISO 15444)"
@@ -174,7 +186,7 @@ class Jpeg2KImageFile(ImageFile.ImageFile):
                 f.seek(pos, 0)
             except:
                 length = -1
-        
+
         self.tile = [('jpeg2k', (0, 0) + self.size, 0,
                       (self.codec, self.reduce, self.layers, fd, length))]
 

Tests/test_file_jpeg2k.py

@@ -120,6 +120,42 @@ class TestFileJpeg2k(PillowTestCase):
         self.assertEqual(j2k.mode, 'RGBA')
         self.assertEqual(jp2.mode, 'RGBA')
 
+    def test_16bit_monochrome_has_correct_mode(self):
+
+        j2k = Image.open('Tests/images/16bit.cropped.j2k')
+        jp2 = Image.open('Tests/images/16bit.cropped.jp2')
+
+        j2k.load()
+        jp2.load()
+
+        self.assertEqual(j2k.mode, 'I;16')
+        self.assertEqual(jp2.mode, 'I;16')
+
+    def test_16bit_monchrome_jp2_like_tiff(self):
+
+        tiff_16bit = Image.open('Tests/images/16bit.cropped.tif')
+        jp2 = Image.open('Tests/images/16bit.cropped.jp2')
+        self.assert_image_similar(jp2, tiff_16bit, 1e-3)
+
+    def test_16bit_monchrome_j2k_like_tiff(self):
+
+        tiff_16bit = Image.open('Tests/images/16bit.cropped.tif')
+        j2k = Image.open('Tests/images/16bit.cropped.j2k')
+        self.assert_image_similar(j2k, tiff_16bit, 1e-3)
+
+    def test_16bit_j2k_roundtrips(self):
+
+        j2k = Image.open('Tests/images/16bit.cropped.j2k')
+        im = self.roundtrip(j2k)
+        self.assert_image_equal(im, j2k)
+
+    def test_16bit_jp2_roundtrips(self):
+
+        jp2 = Image.open('Tests/images/16bit.cropped.jp2')
+        im = self.roundtrip(jp2)
+        self.assert_image_equal(im, jp2)
+
+
 if __name__ == '__main__':
     unittest.main()
 

libImaging/Jpeg2KDecode.c

@@ -135,6 +135,56 @@ j2ku_gray_l(opj_image_t *in, const JPEG2KTILEINFO *tileinfo,
     }
 }
 
+
+static void
+j2ku_gray_i(opj_image_t *in, const JPEG2KTILEINFO *tileinfo,
+            const UINT8 *tiledata, Imaging im)
+{
+    unsigned x0 = tileinfo->x0 - in->x0, y0 = tileinfo->y0 - in->y0;
+    unsigned w = tileinfo->x1 - tileinfo->x0;
+    unsigned h = tileinfo->y1 - tileinfo->y0;
+
+    int shift = 16 - in->comps[0].prec;
+    int offset = in->comps[0].sgnd ? 1 << (in->comps[0].prec - 1) : 0;
+    int csiz = (in->comps[0].prec + 7) >> 3;
+
+    unsigned x, y;
+
+    if (csiz == 3)
+        csiz = 4;
+
+    if (shift < 0)
+        offset += 1 << (-shift - 1);
+
+    switch (csiz) {
+    case 1:
+        for (y = 0; y < h; ++y) {
+            const UINT8 *data = &tiledata[y * w];
+            UINT16 *row = (UINT16 *)im->image[y0 + y] + x0;
+            for (x = 0; x < w; ++x)
+                *row++ = j2ku_shift(offset + *data++, shift);
+        }
+        break;
+    case 2:
+        for (y = 0; y < h; ++y) {
+            const UINT16 *data = (const UINT16 *)&tiledata[2 * y * w];
+            UINT16 *row = (UINT16 *)im->image[y0 + y] + x0;
+            for (x = 0; x < w; ++x)
+                *row++ = j2ku_shift(offset + *data++, shift);
+        }
+        break;
+    case 4:
+        for (y = 0; y < h; ++y) {
+            const UINT32 *data = (const UINT32 *)&tiledata[4 * y * w];
+            UINT16 *row = (UINT16 *)im->image[y0 + y] + x0;
+            for (x = 0; x < w; ++x)
+                *row++ = j2ku_shift(offset + *data++, shift);
+        }
+        break;
+    }
+}
+
+
 static void
 j2ku_gray_rgb(opj_image_t *in, const JPEG2KTILEINFO *tileinfo,
               const UINT8 *tiledata, Imaging im)
@@ -466,6 +516,8 @@ j2ku_sycca_rgba(opj_image_t *in, const JPEG2KTILEINFO *tileinfo,
 
 static const struct j2k_decode_unpacker j2k_unpackers[] = {
     { "L", OPJ_CLRSPC_GRAY, 1, j2ku_gray_l },
+    { "I;16", OPJ_CLRSPC_GRAY, 1, j2ku_gray_i },
+    { "I;16B", OPJ_CLRSPC_GRAY, 1, j2ku_gray_i },
     { "LA", OPJ_CLRSPC_GRAY, 2, j2ku_graya_la },
     { "RGB", OPJ_CLRSPC_GRAY, 1, j2ku_gray_rgb },
     { "RGB", OPJ_CLRSPC_GRAY, 2, j2ku_gray_rgb },

libImaging/Jpeg2KEncode.c

@@ -88,6 +88,22 @@ j2k_pack_l(Imaging im, UINT8 *buf,
     }
 }
 
+static void
+j2k_pack_i16(Imaging im, UINT8 *buf,
+             unsigned x0, unsigned y0, unsigned w, unsigned h)
+{
+    UINT8 *ptr = buf;
+    unsigned x,y;
+    for (y = 0; y < h; ++y) {
+        UINT8 *data = (UINT8 *)(im->image[y + y0] + x0);
+        for (x = 0; x < w; ++x) {
+            *ptr++ = *data++;
+            *ptr++ = *data++;
+        }
+    }
+}
+
+
 static void
 j2k_pack_la(Imaging im, UINT8 *buf,
             unsigned x0, unsigned y0, unsigned w, unsigned h)
@@ -247,6 +263,9 @@ j2k_encode_entry(Imaging im, ImagingCodecState state,
     j2k_pack_tile_t pack;
     int ret = -1;
 
+    unsigned prec = 8;
+    unsigned bpp = 8;
+
     stream = opj_stream_default_create(OPJ_FALSE);
 
     if (!stream) {
@@ -271,6 +290,18 @@ j2k_encode_entry(Imaging im, ImagingCodecState state,
         components = 1;
         color_space = OPJ_CLRSPC_GRAY;
         pack = j2k_pack_l;
+    } else if (strcmp (im->mode, "I;16") == 0){
+        components = 1;
+        color_space = OPJ_CLRSPC_GRAY;
+        pack = j2k_pack_i16;
+        prec = 16;
+        bpp = 12;
+    } else if (strcmp (im->mode, "I;16B") == 0){
+        components = 1;
+        color_space = OPJ_CLRSPC_GRAY;
+        pack = j2k_pack_i16;
+        prec = 16;
+        bpp = 12;
     } else if (strcmp (im->mode, "LA") == 0) {
         components = 2; 
         color_space = OPJ_CLRSPC_GRAY;
@@ -298,8 +329,8 @@ j2k_encode_entry(Imaging im, ImagingCodecState state,
         image_params[n].w = im->xsize;
         image_params[n].h = im->ysize;
         image_params[n].x0 = image_params[n].y0 = 0;
-        image_params[n].prec = 8;
-        image_params[n].bpp = 8;
+        image_params[n].prec = prec;
+        image_params[n].bpp = bpp;
         image_params[n].sgnd = 0;
     }
 
@@ -442,7 +473,7 @@ j2k_encode_entry(Imaging im, ImagingCodecState state,
 
     num_tiles = tiles_x * tiles_y;
 
-    state->buffer = malloc (tile_width * tile_height * components);
+    state->buffer = malloc (tile_width * tile_height * components * prec / 8);
 
     tile_ndx = 0;
     for (y = 0; y < tiles_y; ++y) {
@@ -474,7 +505,7 @@ j2k_encode_entry(Imaging im, ImagingCodecState state,
 
             pack(im, state->buffer, pixx, pixy, pixw, pixh);
 
-            data_size = pixw * pixh * components;
+            data_size = pixw * pixh * components * prec / 8;
 
             if (!opj_write_tile(codec, tile_ndx++, state->buffer,
                                 data_size, stream)) {