migrate image_pipeline docs (#929)

* Migrates image_pipeline overview page
* Migrates CameraInfo wiki page
* Adds links to the other packages in this stack
* Updates depth_image_proc and image_proc to have the overview page properly named and in the TOC

depth_image_proc/doc/index.rst

@@ -1,5 +1,5 @@
-depth_image_proc
-================
+Overview
+========
 
 ``depth_image_proc`` provides basic processing for depth images, much as
 ``image_proc`` does for traditional 2D images. The two packages are
@@ -28,6 +28,7 @@ For an example of ``depth_image_proc`` in practice, examine the contents of
 .. toctree::
    :maxdepth: 2
 
+   self
    components
    tutorials
    changes

image_pipeline/doc/camera_info.rst

@@ -0,0 +1,111 @@
+.. _Camera Info:
+
+Camera Info
+===========
+
+Camera Coordinate System
+------------------------
+Below is a diagram of the camera coordinate system assumed by the
+CameraInfo message. It is a right-handed system, with the world X
+and Y aligned with the image x and y. This is the same coordinate
+system used in OpenCV. It differs from the coordinate system of
+Harley and Zisserman, which has Z forward, Y up, and X to the
+left (looking towards +Z).
+
+|coords|
+
+.. |coords| image:: images/CameraCoords.png
+
+Derivation Diagram
+------------------
+
+Below is a diagram of the various images that are conceptually
+derivable from the CameraInfo message. The boxed variables are
+present in this message.
+
+|camera_info|
+
+.. |camera_info| image:: images/CameraInfo.png
+
+Projection Onto the Original Image
+----------------------------------
+Starting with an initial 3D point X, the position of the corresponding
+image point is found by going right-to-left in the upper half of the
+diagram. The process is summarized by the following equations.
+
+.. code-block:: text
+
+    X' = [R,t]X   transform
+    sx = X'       projection
+    x* = d(x)     distortion
+    q  = Kx*      pixel coordinates
+
+This process uses the K camera matrix and D distortion vector from CameraInfo.
+Ignoring the transform T, you can find the projection of a point X' into the
+original camera frame using these equations. First, the 3D point X' is
+projected onto the normalized, undistorted image via a projection operation
+(division by Z). Then the distortion coefficients are used in the function
+d() to move the point to its distorted position, still in a normalized image.
+Finally, the normalized image is converted to a pixel-coordinate image by
+applying the camera matrix to each image point.
+
+Rectification
+-------------
+Rectification is the process of transforming the input image into an output
+image with the distortion corrected, and optionally the normalized image plane
+transformed by rotation, optinain-image-plane translation, and optionally
+in-image-plane scale.
+
+Simple Monocular Rectification
+------------------------------
+In this case, there is a monocular device with distortion correction only.
+To transform a pixel in the input image into one in the output image, it is
+sent through the K - D - R - K' series of transformations. K - D gets to the
+normalized, undistorted image; the rotation R is the identity because we
+don't want to rotate the normalized undistorted image; and then K' converts
+back to pixel coordinates in the output image. In this case, since there is
+no need of in-image-plane translation, or scaling from the original image,
+so K = K' , and only the K and D elements of CameraInfo are needed.
+The ``camera_calibration`` package does monocular calibration to get K'
+using OpenCV's getOptimalNewCameraMatrix() function with argument
+'alpha'=0.0 that cause K' ≠ K.
+
+Projection onto the output image is by the P matrix, which is formed from K'
+and the optional rotation and translation, in this case the identity and 0,
+respectively. So if K' = K, P is redundant information, and could be formed
+directly from K.
+
+Stereo and Complex Monocular Rectification
+------------------------------------------
+After getting normalized undistorted image using K and D, here we apply a
+transformation to the normalized, undistorted image: each points on this
+image is rotated by R and then is passed to K' get the correspondent pixel
+coordinate on the output image which is translated and scaled by K' with
+respect to the original image. This transformation is important, for example,
+in aligning two images of a stereo pair to lie in the same plane and have
+coincident epipolar lines.
+
+The transform of a pixel from the input to output image is the same as in
+the simple monocular case, except that R need not be the identity, and K'
+need not be equal to K. As a consequence, the normalized undistorted image
+can be rotated in 3D space, and the output image can be translated, scaled
+relative to the original image.
+
+The projection matrix has an additional parameter, a translational offset t.
+This parameter is used in the right stereo camera to reflect its external
+position relative to the left camera. Since the point X in left camera
+frame is transformed to the right camera by [I|t], that means the position
+of the left camera frame origin with respect to the right camera frame is
+given by the vector t in the right camera frame.
+
+Putting this all together, the projection matrix for the rectified output
+image is given by:
+
+.. code-block:: text
+
+    P = K' [I|t].
+
+Note that in this case the internal camera parameters of the output image,
+K', can be different from the input image, so P cannot be formed just
+from K and D. And the I is the 3x3 rotation matrix representing left
+camera frame in the right, not the identity.

image_pipeline/doc/conf.py

@@ -0,0 +1,193 @@
+# Copyright 2024 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -*- coding: utf-8 -*-
+#
+# Configuration file for the Sphinx documentation builder.
+#
+# This file does only contain a selection of the most common options. For a
+# full list see the documentation:
+# http://www.sphinx-doc.org/en/master/config
+
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+import os
+import sys
+sys.path.insert(0, os.path.abspath('.'))
+
+
+# -- Project information -----------------------------------------------------
+
+project = 'image_pipeline'
+copyright = '2008-2024, Open Source Robotics Foundation, Inc.'  # noqa
+author = 'Open Source Robotics Foundation, Inc.'
+
+# The short X.Y version
+version = ''
+# The full version, including alpha/beta/rc tags
+release = '3.2.1'
+
+
+# -- General configuration ---------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#
+# needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    'sphinx.ext.autodoc',
+    'sphinx.ext.autosummary',
+    'sphinx.ext.doctest',
+    'sphinx.ext.coverage',
+    'sphinx_rtd_theme',
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix(es) of source filenames.
+# You can specify multiple suffix as a list of string:
+#
+# source_suffix = ['.rst', '.md']
+source_suffix = '.rst'
+
+# The master toctree document.
+master_doc = 'index'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#
+# This is also used if you do content translation via gettext catalogs.
+# Usually you set "language" from the command line for these cases.
+language = None
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = []
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = None
+
+
+# -- Options for HTML output -------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = 'sphinx_rtd_theme'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#
+# html_theme_options = {}
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = []
+
+# Custom sidebar templates, must be a dictionary that maps document names
+# to template names.
+#
+# The default sidebars (for documents that don't match any pattern) are
+# defined by theme itself.  Builtin themes are using these templates by
+# default: ``['localtoc.html', 'relations.html', 'sourcelink.html',
+# 'searchbox.html']``.
+#
+# html_sidebars = {}
+
+
+# -- Options for HTMLHelp output ---------------------------------------------
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'image_pipeline_doc'
+
+
+# -- Options for LaTeX output ------------------------------------------------
+
+latex_elements = {
+    # The paper size ('letterpaper' or 'a4paper').
+    #
+    # 'papersize': 'letterpaper',
+
+    # The font size ('10pt', '11pt' or '12pt').
+    #
+    # 'pointsize': '10pt',
+
+    # Additional stuff for the LaTeX preamble.
+    #
+    # 'preamble': '',
+
+    # Latex figure (float) alignment
+    #
+    # 'figure_align': 'htbp',
+}
+
+
+# -- Options for manual page output ------------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    (master_doc, 'image_pipeline', 'image_pipeline Documentation',
+     [author], 1)
+]
+
+
+# -- Options for Texinfo output ----------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    (master_doc, 'image_pipeline', 'image_pipeline Documentation',
+     author, 'image_pipeline', 'ROS 2 components for image processing.',
+     'Miscellaneous'),
+]
+
+
+# -- Options for Epub output -------------------------------------------------
+
+# Bibliographic Dublin Core info.
+epub_title = project
+
+# The unique identifier of the text. This can be a ISBN number
+# or the project homepage.
+#
+# epub_identifier = ''
+
+# A unique identification for the text.
+#
+# epub_uid = ''
+
+# A list of files that should not be packed into the epub file.
+epub_exclude_files = ['search.html']
+
+
+# -- Extension configuration -------------------------------------------------
+
+autoclass_content = 'both'
+
+autodoc_default_options = {
+    'members': True,  # document members
+    'undoc-members': True,  # also document members without documentation
+}

image_pipeline/doc/index.rst

@@ -0,0 +1,45 @@
+Overview
+========
+
+The ``image_pipeline`` stack is designed to process raw camera images
+into useful inputs to vision algorithms: rectified mono/color images,
+stereo disparity images, and stereo point clouds. Components include:
+
+ * **Calibration**: Cameras must be calibrated in order to relate the
+   images they produce to the three-dimensional world. The
+   ``camera_calibration`` package provides tools to calibrate monocular
+   and stereo cameras in your ROS system. The :ref:`Camera Info` page
+   provides a detailed description of the parameters used by the
+   pipeline.
+ * **Monocular processing**: The raw image stream can be piped through
+   the ``image_proc`` node to remove camera distortion. The node also
+   performs color interpolation for Bayer pattern color cameras.
+ * **Stereo processing**: The ``stereo_image_proc`` package performs
+   the duties of ``image_proc`` for a pair of cameras co-calibrated
+   for stereo vision. It also uses stereo processing to produce
+   disparity images and point clouds.
+ * **Depth processing**: ``depth_image_proc`` provides components
+   for processing depth images (as produced by the Kinect,
+   time-of-flight cameras, etc.), such as producing point clouds.
+ * **Visualization**: The ``image_view`` package provides a lightweight
+   alternative to ``rviz2`` for viewing an image topic. It also includes
+   a ``stereo_view`` tool for viewing stereo pairs and disparity images.
+
+.. toctree::
+   :maxdepth: 2
+
+   self
+   camera_info
+   camera_calibration <../camera_calibration/index.html#http://>
+   depth_image_proc <../depth_image_proc/index.html#http://>
+   image_proc <../image_proc/index.html#http://>
+   image_publisher <../image_publisher/index.html#http://>
+   image_rotate <../image_rotate/index.html#http://>
+   image_view <../depth/image_view/index.html#http://>
+   stereo_image_proc <../depth/stereo_image_proc/index.html#http://>
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`search`

image_pipeline/package.xml

@@ -34,5 +34,6 @@
 
   <export>
     <build_type>ament_cmake</build_type>
+    <rosdoc2>rosdoc2.yaml</rosdoc2>
   </export>
 </package>

image_pipeline/rosdoc2.yaml

@@ -0,0 +1,20 @@
+type: 'rosdoc2 config'
+version: 1
+
+---
+
+settings:
+    generate_package_index: false
+    always_run_doxygen: false
+    enable_breathe: false
+    enable_exhale: false
+    always_run_sphinx_apidoc: false
+    override_build_type: 'ament_python'
+    python_source: 'doc'
+
+builders:
+    - sphinx: {
+        name: 'image_pipeline',
+        sphinx_sourcedir: 'doc',
+        output_dir: ''
+    }