Merge pull request #1261 from radarhere/nframes

Provide n_frames attribute to multi-frame formats

PIL/DcxImagePlugin.py

@@ -62,6 +62,10 @@ class DcxImageFile(PcxImageFile):
         self.__fp = self.fp
         self.seek(0)
 
+    @property
+    def n_frames(self):
+        return len(self._offset)
+
     def seek(self, frame):
         if frame >= len(self._offset):
             raise EOFError("attempt to seek outside DCX directory")

PIL/FliImagePlugin.py

@@ -86,9 +86,10 @@ class FliImageFile(ImageFile.ImageFile):
         self.palette = ImagePalette.raw("RGB", b"".join(palette))
 
         # set things up to decode first frame
-        self.frame = -1
+        self.__frame = -1
         self.__fp = self.fp
-
+        self.__rewind = self.fp.tell()
+        self._n_frames = None
         self.seek(0)
 
     def _palette(self, palette, shift):
@@ -109,11 +110,35 @@ class FliImageFile(ImageFile.ImageFile):
                 palette[i] = (r, g, b)
                 i += 1
 
-    def seek(self, frame):
+    @property
+    def n_frames(self):
+        if self._n_frames is None:
+            current = self.tell()
+            try:
+                while True:
+                    self.seek(self.tell() + 1)
+            except EOFError:
+                self._n_frames = self.tell() + 1
+            self.seek(current)
+        return self._n_frames
 
-        if frame != self.frame + 1:
+    def seek(self, frame):
+        if frame == self.__frame:
+            return
+        if frame < self.__frame:
+            self._seek(0)
+        for f in range(self.__frame + 1, frame + 1):
+            self._seek(f)
+
+    def _seek(self, frame):
+        if frame == 0:
+            self.__frame = -1
+            self.__fp.seek(self.__rewind)
+            self.__offset = 128
+
+        if frame != self.__frame + 1:
             raise ValueError("cannot seek to frame %d" % frame)
-        self.frame = frame
+        self.__frame = frame
 
         # move to next frame
         self.fp = self.__fp
@@ -128,11 +153,10 @@ class FliImageFile(ImageFile.ImageFile):
         self.decodermaxblock = framesize
         self.tile = [("fli", (0, 0)+self.size, self.__offset, None)]
 
-        self.__offset = self.__offset + framesize
+        self.__offset += framesize
 
     def tell(self):
-
-        return self.frame
+        return self.__frame
 
 #
 # registry

PIL/GifImagePlugin.py

@@ -87,9 +87,30 @@ class GifImageFile(ImageFile.ImageFile):
 
         self.__fp = self.fp  # FIXME: hack
         self.__rewind = self.fp.tell()
-        self.seek(0)  # get ready to read first frame
+        self._n_frames = None
+        self._seek(0)  # get ready to read first frame
+
+    @property
+    def n_frames(self):
+        if self._n_frames is None:
+            current = self.tell()
+            try:
+                while True:
+                    self.seek(self.tell() + 1)
+            except EOFError:
+                self._n_frames = self.tell() + 1
+            self.seek(current)
+        return self._n_frames
 
     def seek(self, frame):
+        if frame == self.__frame:
+            return
+        if frame < self.__frame:
+            self._seek(0)
+        for f in range(self.__frame + 1, frame + 1):
+            self._seek(f)
+
+    def _seek(self, frame):
 
         if frame == 0:
             # rewind

PIL/ImImagePlugin.py

@@ -260,6 +260,10 @@ class ImImageFile(ImageFile.ImageFile):
             self.tile = [("raw", (0, 0)+self.size, offs,
                          (self.rawmode, 0, -1))]
 
+    @property
+    def n_frames(self):
+        return self.info[FRAMES]
+
     def seek(self, frame):
 
         if frame < 0 or frame >= self.info[FRAMES]:

PIL/MicImagePlugin.py

@@ -71,6 +71,10 @@ class MicImageFile(TiffImagePlugin.TiffImageFile):
 
         self.seek(0)
 
+    @property
+    def n_frames(self):
+        return len(self.images)
+
     def seek(self, frame):
 
         try:

PIL/MpoImagePlugin.py

@@ -62,6 +62,10 @@ class MpoImageFile(JpegImagePlugin.JpegImageFile):
     def load_seek(self, pos):
         self.__fp.seek(pos)
 
+    @property
+    def n_frames(self):
+        return self.__framecount
+
     def seek(self, frame):
         if frame < 0 or frame >= self.__framecount:
             raise EOFError("no more images in MPO file")

PIL/PsdImagePlugin.py

@@ -132,6 +132,10 @@ class PsdImageFile(ImageFile.ImageFile):
         self._fp = self.fp
         self.frame = 0
 
+    @property
+    def n_frames(self):
+        return len(self.layers)
+
     def seek(self, layer):
         # seek to given layer (1..max)
         if layer == self.frame:

PIL/SpiderImagePlugin.py

@@ -127,12 +127,12 @@ class SpiderImageFile(ImageFile.ImageFile):
         if self.istack == 0 and self.imgnumber == 0:
             # stk=0, img=0: a regular 2D image
             offset = hdrlen
-            self.nimages = 1
+            self._nimages = 1
         elif self.istack > 0 and self.imgnumber == 0:
             # stk>0, img=0: Opening the stack for the first time
             self.imgbytes = int(h[12]) * int(h[2]) * 4
             self.hdrlen = hdrlen
-            self.nimages = int(h[26])
+            self._nimages = int(h[26])
             # Point to the first image in the stack
             offset = hdrlen * 2
             self.imgnumber = 1
@@ -154,6 +154,10 @@ class SpiderImageFile(ImageFile.ImageFile):
                 (self.rawmode, 0, 1))]
         self.__fp = self.fp  # FIXME: hack
 
+    @property
+    def n_frames(self):
+        return self._nimages
+
     # 1st image index is zero (although SPIDER imgnumber starts at 1)
     def tell(self):
         if self.imgnumber < 1:
@@ -164,7 +168,7 @@ class SpiderImageFile(ImageFile.ImageFile):
     def seek(self, frame):
         if self.istack == 0:
             return
-        if frame >= self.nimages:
+        if frame >= self._nimages:
             raise EOFError("attempt to seek past end of file")
         self.stkoffset = self.hdrlen + frame * (self.hdrlen + self.imgbytes)
         self.fp = self.__fp

PIL/TiffImagePlugin.py

@@ -648,6 +648,8 @@ class TiffImageFile(ImageFile.ImageFile):
         self.__first = self.__next = self.ifd.i32(ifh, 4)
         self.__frame = -1
         self.__fp = self.fp
+        self._frame_pos = []
+        self._n_frames = None
 
         if Image.DEBUG:
             print("*** TiffImageFile._open ***")
@@ -657,28 +659,30 @@ class TiffImageFile(ImageFile.ImageFile):
         # and load the first frame
         self._seek(0)
 
+    @property
+    def n_frames(self):
+        if self._n_frames is None:
+            current = self.tell()
+            try:
+                while True:
+                    self._seek(self.tell() + 1)
+            except EOFError:
+                self._n_frames = self.tell() + 1
+            self.seek(current)
+        return self._n_frames
+
     def seek(self, frame):
         "Select a given frame as current image"
-        if frame < 0:
-            frame = 0
-        self._seek(frame)
+        self._seek(max(frame, 0))  # Questionable backwards compatibility.
         # Create a new core image object on second and
         # subsequent frames in the image. Image may be
         # different size/mode.
         Image._decompression_bomb_check(self.size)
         self.im = Image.core.new(self.mode, self.size)
 
-    def tell(self):
-        "Return the current frame number"
-        return self._tell()
-
     def _seek(self, frame):
         self.fp = self.__fp
-        if frame < self.__frame:
-            # rewind file
-            self.__frame = -1
-            self.__next = self.__first
-        while self.__frame < frame:
+        while len(self._frame_pos) <= frame:
             if not self.__next:
                 raise EOFError("no more images in TIFF file")
             if Image.DEBUG:
@@ -688,14 +692,19 @@ class TiffImageFile(ImageFile.ImageFile):
             # was passed to libtiff, invalidating the buffer
             self.fp.tell()
             self.fp.seek(self.__next)
+            self._frame_pos.append(self.__next)
             if Image.DEBUG:
                 print("Loading tags, location: %s" % self.fp.tell())
             self.tag.load(self.fp)
             self.__next = self.tag.next
             self.__frame += 1
+        self.fp.seek(self._frame_pos[frame])
+        self.tag.load(self.fp)
+        self.__frame = frame
         self._setup()
 
-    def _tell(self):
+    def tell(self):
+        "Return the current frame number"
         return self.__frame
 
     def _decoder(self, rawmode, layer, tile=None):

Tests/test_file_dcx.py

@@ -30,6 +30,10 @@ class TestFileDcx(PillowTestCase):
         # Assert
         self.assertEqual(frame, 0)
 
+    def test_n_frames(self):
+        im = Image.open(TEST_FILE)
+        self.assertEqual(im.n_frames, 1)
+
     def test_seek_too_far(self):
         # Arrange
         im = Image.open(TEST_FILE)

Tests/test_file_fli.py

@@ -18,6 +18,10 @@ class TestFileFli(PillowTestCase):
         self.assertEqual(im.size, (128, 128))
         self.assertEqual(im.format, "FLI")
 
+    def test_n_frames(self):
+        im = Image.open(test_file)
+        self.assertEqual(im.n_frames, 2)
+
 
 if __name__ == '__main__':
     unittest.main()

Tests/test_file_gif.py

@@ -134,6 +134,10 @@ class TestFileGif(PillowTestCase):
         except EOFError:
             self.assertEqual(framecount, 5)
 
+    def test_n_frames(self):
+        im = Image.open("Tests/images/iss634.gif")
+        self.assertEqual(im.n_frames, 43)
+
     def test_dispose_none(self):
         img = Image.open("Tests/images/dispose_none.gif")
         try:

Tests/test_file_im.py

@@ -0,0 +1,33 @@
+from helper import unittest, PillowTestCase, hopper
+
+from PIL import Image
+
+# sample im
+TEST_IM = "Tests/images/hopper.im"
+
+
+class TestFileIm(PillowTestCase):
+
+    def test_sanity(self):
+        im = Image.open(TEST_IM)
+        im.load()
+        self.assertEqual(im.mode, "RGB")
+        self.assertEqual(im.size, (128, 128))
+        self.assertEqual(im.format, "IM")
+
+    def test_n_frames(self):
+        im = Image.open(TEST_IM)
+        self.assertEqual(im.n_frames, 1)
+
+    def test_roundtrip(self):
+        out = self.tempfile('temp.im')
+        im = hopper()
+        im.save(out)
+        reread = Image.open(out)
+
+        self.assert_image_equal(reread, im)
+
+if __name__ == '__main__':
+    unittest.main()
+
+# End of file

Tests/test_file_mpo.py

@@ -95,6 +95,10 @@ class TestFileMpo(PillowTestCase):
             im.seek(0)
             self.assertEqual(im.tell(), 0)
 
+    def test_n_frames(self):
+        im = Image.open("Tests/images/sugarshack.mpo")
+        self.assertEqual(im.n_frames, 2)
+
     def test_image_grab(self):
         for test_file in test_files:
             im = Image.open(test_file)

Tests/test_file_psd.py

@@ -16,6 +16,13 @@ class TestImagePsd(PillowTestCase):
         self.assertEqual(im.size, (128, 128))
         self.assertEqual(im.format, "PSD")
 
+    def test_n_frames(self):
+        im = Image.open("Tests/images/hopper_merged.psd")
+        self.assertEqual(im.n_frames, 1)
+
+        im = Image.open(test_file)
+        self.assertEqual(im.n_frames, 2)
+
 
 if __name__ == '__main__':
     unittest.main()

Tests/test_file_spider.py

@@ -42,6 +42,10 @@ class TestImageSpider(PillowTestCase):
         # Assert
         self.assertEqual(index, 0)
 
+    def test_n_frames(self):
+        im = Image.open(TEST_FILE)
+        self.assertEqual(im.n_frames, 1)
+
     def test_loadImageSeries(self):
         # Arrange
         not_spider_file = "Tests/images/hopper.ppm"

Tests/test_file_tiff.py

@@ -150,6 +150,13 @@ class TestFileTiff(PillowTestCase):
         self.assertEqual(
             im.getextrema(), (-3.140936851501465, 3.140684127807617))
 
+    def test_n_frames(self):
+        im = Image.open('Tests/images/multipage-lastframe.tif')
+        self.assertEqual(im.n_frames, 1)
+
+        im = Image.open('Tests/images/multipage.tiff')
+        self.assertEqual(im.n_frames, 3)
+
     def test_multipage(self):
         # issue #862
         im = Image.open('Tests/images/multipage.tiff')