Added support for images watermarking

HISTORY.rst

@@ -21,3 +21,11 @@ History
 * Dropped shadow support for units
 * Added outline support for units
 * Made unit's font config as a separate class
+
+
+0.4.0 (2017-09-14)
+------------------
+
+* Added ability to add watermarks to images 
+
+

README.rst

@@ -26,13 +26,13 @@ nider
         :target: https://pypi.python.org/pypi/nider
         :alt: License
 
-Python package to add text to images, textures and different backgrounds
+Python package for text images generation and watermarking
 
 
 * Free software: MIT license
 * Documentation: https://nider.readthedocs.io.
 
-``nider`` is an approach to make generation of text based images simple yet flexible. Creating of an image is as simple as describing units you want to be rendered to the image and choosing a method that will be used for drawing.
+``nider`` is an approach to make generation of text images simple yet flexible. Creating of an image is as simple as describing units you want to be rendered to the image and choosing a method that will be used for drawing.
 
 ************
 Installation
@@ -73,21 +73,32 @@ All of the featured images were drawn using ``nider`` package. Code used to gene
 
 
 Example 1
-========
+=========
 .. image:: https://github.com/pythad/nider/raw/master/examples/example1/result.png
         :alt: example1
 
 Example 2
-========
+=========
 .. image:: https://github.com/pythad/nider/raw/master/examples/example2/result.png
         :alt: example2
 
 Example 3
-========
+=========
 .. image:: https://github.com/pythad/nider/raw/master/examples/example3/result.png
         :alt: example3
 
 Example 4
-========
+=========
 .. image:: https://github.com/pythad/nider/raw/master/examples/example4/result.png
         :alt: example4
+
+Watermark example 1
+===================
+.. image:: https://github.com/pythad/nider/raw/master/examples/add_watermark_example/result.jpg
+        :alt: add_watermark_example
+
+Watermark example 2
+===================
+.. image:: https://github.com/pythad/nider/raw/master/examples/draw_on_bg_with_watermark_example/result.png
+        :alt: draw_on_bg_with_watermark_example
+

docs/nider.rst

@@ -11,7 +11,7 @@ nider\.models module
 --------------------
 
 .. automodule:: nider.models
-    :members: Header, Paragraph, Linkback, Content, Image, FacebookSquarePost, FacebookLandscapePost, TwitterPost, TwitterLargeCard, InstagramSquarePost, InstagramPortraitPost, InstagramLandscapePost
+    :members: Header, Paragraph, Linkback, Watermark, Content, Image, FacebookSquarePost, FacebookLandscapePost, TwitterPost, TwitterLargeCard, InstagramSquarePost, InstagramPortraitPost, InstagramLandscapePost
 
 nider\.exceptions module
 ------------------------

docs/usage.rst

@@ -34,8 +34,10 @@ Example
 
     from nider.core import Font
     from nider.core import Outline
+
     from nider.models import Header
 
+
     header = Header(text='Your super interesting title!',
                     font=Font('/home/me/.local/share/fonts/Roboto/Roboto-Bold.ttf', 30),
                     text_width=40,
@@ -59,8 +61,10 @@ Example
 
     from nider.core import Font
     from nider.core import Outline
+
     from nider.models import Paragraph
 
+
     para = Paragraph(text='Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.',
                      font=Font('/home/me/.local/share/fonts/Roboto/Roboto-Bold.ttf', 30),
                      text_width=65,
@@ -82,8 +86,10 @@ Example
 
     from nider.core import Font
     from nider.core import Outline
+
     from nider.models import Linkback
 
+
     linkback = Linkback(text='foo.com | @username',
                         font=Font('/home/me/.local/share/fonts/Roboto/Roboto-Bold.ttf', 30),
                         color='#ededed',
@@ -118,6 +124,7 @@ Example
     from nider.models import Linkback
     from nider.models import Paragraph
 
+
     para = Paragraph(...)
 
     linkback = Linkback(...)
@@ -144,6 +151,7 @@ Example
     from nider.models import Content
     from nider.models import Image
 
+
     content = Content(...)
 
     img = Image(content,
@@ -211,6 +219,7 @@ Example
     from nider.models import Content
     from nider.models import Image
 
+
     content = Content(...)
 
     img = Image(content,
@@ -229,7 +238,7 @@ Check the full example `here <https://github.com/pythad/nider/blob/master/exampl
 ``nider`` comes with a `huge bundle of textures <https://github.com/pythad/nider/tree/master/nider/textures>`_. As for now you need to copy them to your machine if you want to use any of them.
 
 ``Image.draw_on_bg``
-=========================
+====================
 
 .. automethod:: nider.models.Image.draw_on_bg
 
@@ -241,6 +250,7 @@ Example
     from nider.models import Content
     from nider.models import Image
 
+
     content = Content(...)
 
     img = Image(content,
@@ -254,7 +264,7 @@ Example
 Check the full example `here <https://github.com/pythad/nider/blob/master/examples/draw_on_bg_example/script.py>`_ .
 
 ``Image.draw_on_image``
-=========================
+=======================
 
 .. automethod:: nider.models.Image.draw_on_image
 
@@ -266,6 +276,7 @@ Examples
     from nider.models import Content
     from nider.models import Image
 
+
     content = Content(...)
 
     img = Image(content,
@@ -290,4 +301,68 @@ Check the full example `here <https://github.com/pythad/nider/blob/master/exampl
 
 ============
 
-That's it. After any of draw methods has been called and successfully completed the new image will be saved to ``Image.fullpath``.
+That's it. After any of draw methods has been called and successfully completed the new image will be saved to ``Image.fullpath``.
+
+*****************
+Adding watermarks
+*****************
+
+``nider`` comes with built-in support for adding watermarks to your images.
+
+First of all you need to create an instanse of :class:`nider.models.Watermark` class.
+
+.. autoclass:: nider.models.Watermark
+
+
+Example
+=======
+
+.. code-block:: python
+
+    watermark = Watermark(text='COPYRIGHT',
+                          font=Font('/home/me/.local/share/fonts/Roboto/Roboto-Bold.ttf'),
+                          color='#111',
+                          cross=True,
+                          rotate_angle=-45,
+                          opacity=0.35
+                          )
+
+============
+
+After this you can either add watermark to you ``Content`` instance and draw watermark on ``nider`` generated images:
+
+.. code-block:: python
+
+    from nider.models import Content
+    from nider.models import Image
+    from nider.models import Watermark
+
+
+    watermark = Watermark(...)
+
+    content = Content(..., watermark=watermark)
+
+    img = Image(content,
+                fullpath='example.png',
+                width=500,
+                height=500
+                )
+
+    img.draw_on_bg('#efefef')
+
+or you can add a watermark to an existing image using :func:`nider.tools.add_watermark`:
+
+.. autofunction:: nider.tools.add_watermark
+
+Example
+=======
+
+.. code-block:: python
+
+    from nider.models import Watermark
+
+    from nider.tools import add_watermark
+
+
+    watermark = Watermark(...)
+    add_watermark('path/to/my/img', watermark)

examples/add_watermark_example/script.py

@@ -0,0 +1,17 @@
+from nider.core import Font
+
+from nider.models import Watermark
+
+from nider.tools import add_watermark
+
+
+# TODO: change this fontpath to the fontpath on your machine
+roboto_fonts_folder = '/home/ovd/.local/share/fonts/Roboto/'
+
+watermark = Watermark(text='COPYRIGHT',
+                      font=Font(roboto_fonts_folder + 'Roboto-Medium.ttf', 20),
+                      color='#111',
+                      cross=True
+                      )
+
+add_watermark('bg.jpg', watermark, 'result.jpg')

examples/draw_on_bg_with_watermark_example/script.py

@@ -0,0 +1,33 @@
+from nider.core import Font
+
+from nider.models import Paragraph
+from nider.models import Watermark
+from nider.models import Content
+from nider.models import Image
+
+
+# TODO: change this fontpath to the fontpath on your machine
+fonts_folder = '/home/ovd/.local/share/fonts/Roboto/'
+
+para = Paragraph(text='Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.',
+                 font=Font(fonts_folder + 'Roboto-Medium.ttf', 20),
+                 text_width=49,
+                 align='center',
+                 color='#121212'
+                 )
+
+watermark = Watermark(text='COPYRIGHT',
+                      font=Font(fonts_folder + 'Roboto-Medium.ttf'),
+                      color='#111',
+                      cross=True
+                      )
+
+content = Content(para, watermark=watermark)
+
+img = Image(content,
+            width=500,
+            height=500,
+            fullpath='result.png',
+            )
+
+img.draw_on_bg('#efefef')

nider/core.py

@@ -4,6 +4,7 @@ from nider.utils import get_font
 
 from nider.mixins import MultilineTextMixin
 from nider.mixins import AlignMixin
+
 from nider.colors.utils import color_to_rgb
 
 
@@ -18,6 +19,7 @@ class Font:
         nider.exceptions.DefaultFontWarning: if ``path`` is ``None``.
         nider.exceptions.FontNotFoundWarning: if ``path`` does not exist.
     '''
+    is_default = False
 
     def __init__(self, path=None, size=18):
         self.path = path
@@ -27,6 +29,7 @@ class Font:
     def _set_font(self):
         '''Sets object's font'''
         self.font = get_font(self.path, self.size)
+        self.is_default = self.font.is_default
 
 
 class Outline:
@@ -50,7 +53,17 @@ class Outline:
 
 
 class Text:
-    '''Base class for the text'''
+    '''
+    Args:
+        text (str): text to use.
+        font (nider.core.Font): font object that represents text's font.
+        color (str): string that represents a color. Must be compatible with `PIL.ImageColor <http://pillow.readthedocs.io/en/latest/reference/ImageColor.html>`_ `color names <http://pillow.readthedocs.io/en/latest/reference/ImageColor.html#color-names>`_
+        outline (nider.core.Outline): outline object that represents text's outline.
+
+    Raises:
+        nider.exceptions.DefaultFontWarning: if ``font.path`` is ``None``.
+        nider.exceptions.FontNotFoundWarning: if ``font.path`` does not exist.
+    '''
 
     def __init__(self, text, font, color, outline):
         self._set_text(text)
@@ -69,7 +82,19 @@ class Text:
 
 
 class MultilineText(MultilineTextMixin, Text):
-    '''Base class for the multiline text'''
+    '''
+    Args:
+        text (str): text used for the unit.
+        font (nider.core.Font): font object that represents text's font.
+        text_width (int): units's text width - number of characters in a line.
+        line_padding (int): unit's line padding - padding (in pixels) between the lines.
+        color (str): string that represents a color. Must be compatible with `PIL.ImageColor <http://pillow.readthedocs.io/en/latest/reference/ImageColor.html>`_ `color names <http://pillow.readthedocs.io/en/latest/reference/ImageColor.html#color-names>`_.
+        outline (nider.core.Outline): outline object that represents text's outline.
+
+    Raises:
+        AttributeError: if ``text_width`` < 0.
+        nider.exceptions.DefaultFontWarning: if ``font.path`` is ``None``.
+        nider.exceptions.FontNotFoundWarning: if ``font.path`` does not exist.'''
 
     def __init__(self, text_width, line_padding, *args, **kwargs):
         MultilineTextMixin.__init__(

nider/exceptions.py

@@ -25,6 +25,14 @@ class FontNotFoundWarning(ImageGeneratorWarning):
             "Font {} hasn't been found. Default font has been set instead".format(fontpath_provided))
 
 
+class FontNotFoundException(ImageGeneratorWarning):
+    '''Exception raised when font cannot be found'''
+
+    def __init__(self, fontpath_provided):
+        super().__init__(
+            "Font {} hasn't been found.".format(fontpath_provided))
+
+
 class DefaultFontWarning(ImageGeneratorWarning):
     '''Warning raised when default font was used'''
 

nider/models.py

@@ -4,7 +4,10 @@ import warnings
 
 from PIL import Image as PIL_Image
 from PIL import ImageDraw
+from PIL import ImageEnhance
 
+from nider.core import Font
+from nider.core import Text
 from nider.core import MultilineTextUnit
 from nider.core import SingleLineTextUnit
 
@@ -45,7 +48,7 @@ class Linkback(SingleLineTextUnit):
         bottom_padding (int): linkback’s bottom padding - padding (in pixels) between the bottom of the image and the linkback itself.
 
     Raises:
-        nider.exceptions.InvalidAlignException: if ``align` is not supported by nider.
+        nider.exceptions.InvalidAlignException: if ``align`` is not supported by nider.
         nider.exceptions.DefaultFontWarning: if ``font.path`` is ``None``.
         nider.exceptions.FontNotFoundWarning: if ``font.path`` does not exist.
     '''
@@ -63,6 +66,61 @@ class Linkback(SingleLineTextUnit):
         self.height += self.bottom_padding
 
 
+class Watermark(Text):
+    '''Class that represents a watermark used in images
+
+    Args:
+        text (str): text to use.
+        font (nider.core.Font): font object that represents text's font.
+        color (str): string that represents a color. Must be compatible with `PIL.ImageColor <http://pillow.readthedocs.io/en/latest/reference/ImageColor.html>`_ `color names <http://pillow.readthedocs.io/en/latest/reference/ImageColor.html#color-names>`_
+        outline (nider.core.Outline): outline object that represents text's outline.
+        cross (bool): boolean flag that indicates whether watermark has to be drawn with a cross.
+        rotate_angle (int): angle to which watermark's text has to be rotated.
+        opacity (0 <= float <= 1): opacity level of the watermark (applies to both the text and the cross).
+
+    Raises:
+        nider.exceptions.ImageGeneratorException: if ``font`` is the default font.
+        nider.exceptions.DefaultFontWarning: if ``font.path`` is ``None``.
+        nider.exceptions.FontNotFoundWarning: if ``font.path`` does not exist.
+
+    Note:
+        Watermark tries to takes all available width of the image so providing ``font.size`` has no affect on the watermark.
+    '''
+
+    def __init__(self, text, font,
+                 color=None, outline=None,
+                 cross=True, rotate_angle=None,
+                 opacity=0.25):
+        if font.is_default:
+            raise ImageGeneratorException(
+                'Watermark cannot be drawn using a default font. Please provide an existing font')
+        super().__init__(text=text, font=font, color=color, outline=outline)
+        self.cross = cross
+        self.rotate_angle = rotate_angle
+        self.opacity = opacity
+
+    def _adjust_fontsize(self, bg_image):
+        text_width, text_height = self.font.getsize(self.text)
+        angle = self.rotate_angle
+
+        # If the width of the image is bigger than the height of the image and we rotate
+        # our watermark it may go beyond the bounding box of the original image,
+        # that's why we need to take into consideration the actual width of the rotated
+        # waterwark inside the original image's bounding box
+        bg_image_w, bg_image_h = bg_image.size
+        if angle and (bg_image_w > bg_image_h):
+            max_wm_w = 2 * \
+                abs(bg_image_h / (2 * math.sin(math.radians(angle))))
+        else:
+            max_wm_w = bg_image_w
+
+        while text_width + text_height < max_wm_w:
+            self.font_object = Font(
+                self.font_object.path, self.font_object.size + 1)
+            self.font = self.font_object.font
+            text_width, text_height = self.font.getsize(self.text)
+
+
 class Content:
     '''Class that aggregates different units into a sigle object
 
@@ -70,6 +128,7 @@ class Content:
         paragraph (nider.models.Paragraph): paragraph used for in the content.
         header (nider.models.Header): header used for in the content.
         linkback (nider.models.Linkback): linkback used for in the content.
+        watermark (nider.models.Watermark): watermark used for in the content.
         padding (int): content's padding - padding (in pixels) between the units.
 
     Raises:
@@ -85,17 +144,18 @@ class Content:
     # but it may changed by in Img._fix_image_size()
     fits = True
 
-    def __init__(self, paragraph=None, header=None, linkback=None, padding=45):
-        if not any((paragraph, header, linkback)):
+    def __init__(self, paragraph=None, header=None, linkback=None, watermark=None, padding=45):
+        if not any((paragraph, header, linkback, watermark)):
             raise ImageGeneratorException(
                 'Content has to consist at least of one unit.')
         self.para = paragraph
         self.header = header
         self.linkback = linkback
+        self.watermark = watermark
         self.padding = padding
         self.depends_on_opposite_to_bg_color = not all(
             unit.color for unit in [
-                self.para, self.header, self.linkback
+                self.para, self.header, self.linkback, self.watermark
             ] if unit
         )
         self._set_content_height()
@@ -123,7 +183,7 @@ class Image:
         description (str): description of the image. Serves as metadata for latter rendering in html. May be used as description text of the image. If no description is provided ``content.paragraph.text`` will be set as the value.
 
     Raises:
-        nider.exceptions.ImageGeneratorException: if the current user has sufficient permissions to create the file at passed ``fullpath``.
+        nider.exceptions.ImageGeneratorException: if the current user doesn't have sufficient permissions to create the file at passed ``fullpath``.
         AttributeError: if width <= 0 or height <= 0.
     '''
 
@@ -224,6 +284,7 @@ class Image:
         self.header = content.header
         self.para = content.para
         self.linkback = content.linkback
+        self.watermark = content.watermark
 
     def _set_fullpath(self, fullpath):
         '''Sets path where to save the image'''
@@ -331,6 +392,8 @@ class Image:
             self._draw_para()
         if self.linkback:
             self._draw_linkback()
+        if self.watermark:
+            self._draw_watermark()
 
     def _draw_header(self):
         '''Draws the header on the image'''
@@ -357,6 +420,54 @@ class Image:
         current_h = self.height - self.linkback.height
         self._draw_unit(current_h, self.linkback)
 
+    def _draw_watermark(self):
+        '''Draws a watermark on the image'''
+        watermark_image = PIL_Image.new('RGBA', self.image.size, (0, 0, 0, 0))
+        self.watermark._adjust_fontsize(self.image)
+        draw = ImageDraw.Draw(watermark_image, 'RGBA')
+        w_width, w_height = self.watermark.font.getsize(self.watermark.text)
+        draw.text(((watermark_image.size[0] - w_width) / 2,
+                   (watermark_image.size[1] - w_height) / 2),
+                  self.watermark.text, font=self.watermark.font,
+                  fill=self.watermark.color)
+
+        if self.watermark.rotate_angle:
+            watermark_image = watermark_image.rotate(
+                self.watermark.rotate_angle, PIL_Image.BICUBIC)
+
+        alpha = watermark_image.split()[3]
+        alpha = ImageEnhance.Brightness(alpha).enhance(self.watermark.opacity)
+        watermark_image.putalpha(alpha)
+
+        # Because watermark can be rotated we create a separate image for cross
+        # so that it doesn't get rotated also. + It's impossible to drawn
+        # on a rotated image
+        if self.watermark.cross:
+            watermark_cross_image = PIL_Image.new(
+                'RGBA', self.image.size, (0, 0, 0, 0))
+            cross_draw = ImageDraw.Draw(watermark_cross_image, 'RGBA')
+            line_width = 1 + int(sum(self.image.size) / 2 * 0.007)
+            cross_draw.line(
+                (0, 0) + watermark_image.size,
+                fill=self.watermark.color,
+                width=line_width
+            )
+            cross_draw.line(
+                (0, watermark_image.size[1], watermark_image.size[0], 0),
+                fill=self.watermark.color,
+                width=line_width
+            )
+            watermark_cross_alpha = watermark_cross_image.split()[3]
+            watermark_cross_alpha = ImageEnhance.Brightness(
+                watermark_cross_alpha).enhance(self.watermark.opacity)
+            watermark_cross_image.putalpha(watermark_cross_alpha)
+            # Adds cross to the watermark
+            watermark_image = PIL_Image.composite(
+                watermark_cross_image, watermark_image, watermark_cross_image)
+
+        self.image = PIL_Image.composite(
+            watermark_image, self.image, watermark_image)
+
     def _draw_unit(self, start_height, unit):
         '''Draws the text and its outline on the image starting at specific height'''
         current_h = start_height

nider/tools.py

@@ -0,0 +1,26 @@
+from nider.models import Image
+from nider.models import Content
+
+
+def add_watermark(image_path, watermark, new_path=None,
+                  image_enhancements=None, image_filters=None):
+    '''Function to add watermarks to images
+
+    Args:
+        image_path (str): path of the image to which watermark has to be added.
+        watermark (nider.models.Watermark): watermark object.
+        new_path (str): path where the image has to be saved. **If set to None (default option), initial image will be overwritten.**
+        image_enhancements (itarable): itarable of tuples, each containing a class from ``PIL.ImageEnhance`` that will be applied and factor - a floating point value controlling the enhancement. Check `documentation <http://pillow.readthedocs.io/en/latest/reference/ImageEnhance.html>`_ of ``PIL.ImageEnhance`` for more info about availabe enhancements.
+        image_filters (itarable): itarable of filters from ``PIL.ImageFilter`` that will be applied. Check `documentation <http://pillow.readthedocs.io/en/latest/reference/ImageFilter.html>`_ of ``PIL.ImageFilter`` for more info about availabe filters.
+
+    Raises:
+        FileNotFoundError: if image file at path ``image_path`` cannot be found.
+        nider.exceptions.ImageGeneratorException: if the current user doesn't have sufficient permissions to create the file at passed ``new_path``.
+    '''
+    if new_path is None:
+        new_path = image_path
+    content = Content(watermark=watermark)
+    new_image = Image(content, fullpath=new_path)
+    new_image.draw_on_image(image_path,
+                            image_enhancements=image_enhancements,
+                            image_filters=image_filters)

nider/utils.py

@@ -29,11 +29,16 @@ def get_font(fontfullpath, fontsize):
     '''
     if fontfullpath is None:
         warnings.warn(DefaultFontWarning())
-        return ImageFont.load_default()
+        font = ImageFont.load_default()
+        font.is_default = True
     elif not os.path.exists(fontfullpath):
         warnings.warn(FontNotFoundWarning(fontfullpath))
-        return ImageFont.load_default()
-    return ImageFont.truetype(fontfullpath, fontsize)
+        font = ImageFont.load_default()
+        font.is_default = True
+    else:
+        font = ImageFont.truetype(fontfullpath, fontsize)
+        font.is_default = False
+    return font
 
 
 def is_path_creatable(pathname):

tests/test_models.py

@@ -9,6 +9,7 @@ from PIL import ImageDraw
 from PIL import ImageEnhance
 from PIL import ImageFilter
 
+from nider.core import Font
 from nider.core import Outline
 from nider.core import MultilineTextUnit
 
@@ -21,6 +22,7 @@ from nider.models import InstagramLandscapePost
 from nider.models import InstagramPortraitPost
 from nider.models import InstagramSquarePost
 from nider.models import Linkback
+from nider.models import Watermark
 from nider.models import Paragraph
 from nider.models import TwitterLargeCard
 from nider.models import TwitterPost
@@ -43,6 +45,13 @@ class TestLinkback(unittest.TestCase):
         self.assertEqual(self.linkback.height, 31)
 
 
+class TestWatermarkBehavior(unittest.TestCase):
+
+    def test_watermark_initialization_with_default_font(self):
+        with self.assertRaises(ImageGeneratorException):
+            Watermark(text='foo', font=Font())
+
+
 class TestContent(unittest.TestCase):
 
     def test_initialization_without_any_units(self):

tests/test_utils.py

@@ -27,11 +27,12 @@ class TestGetFont(unittest.TestCase):
     def test_existent_font(self, load_default_mock,
                            path_exists_mock, truetype_mock):
         path_exists_mock.return_value = True
-        truetype_mock.return_value = 'existent_font'
+        return_mock = mock.MagicMock()
+        truetype_mock.return_value = return_mock
         font = get_font(
             fontfullpath=os.path.abspath('/foo/bar/'),
             fontsize=15)
-        self.assertTrue(font, 'existent_font')
+        self.assertTrue(font, return_mock)
         self.assertFalse(load_default_mock.called)