Merge pull request #8253 from adl1995:master

* Update linux_install.markdown

Grammar improvements, fixed typos.

* Update tutorials.markdown

Improvements in grammar.

* Update table_of_content_calib3d.markdown

* Update camera_calibration_square_chess.markdown

Improvements in grammar. Added answer.

* Update tutorials.markdown

* Update erosion_dilatation.markdown

* Update table_of_content_imgproc.markdown

* Update warp_affine.markdown

* Update camera_calibration_square_chess.markdown

Removed extra space.

* Update gpu_basics_similarity.markdown

Grammatical improvements, fixed typos.

* Update trackbar.markdown

Improvement for better understanding.

doc/tutorials/calib3d/camera_calibration_square_chess/camera_calibration_square_chess.markdown

@@ -5,7 +5,7 @@ The goal of this tutorial is to learn how to calibrate a camera given a set of c
 
 *Test data*: use images in your data/chess folder.
 
--   Compile opencv with samples by setting BUILD_EXAMPLES to ON in cmake configuration.
+-   Compile OpenCV with samples by setting BUILD_EXAMPLES to ON in cmake configuration.
 
 -   Go to bin folder and use imagelist_creator to create an XML/YAML list of your images.
 
@@ -14,32 +14,32 @@ The goal of this tutorial is to learn how to calibrate a camera given a set of c
 Pose estimation
 ---------------
 
-Now, let us write a code that detects a chessboard in a new image and finds its distance from the
-camera. You can apply the same method to any object with known 3D geometry that you can detect in an
+Now, let us write code that detects a chessboard in an image and finds its distance from the
+camera. You can apply this method to any object with known 3D geometry; which you detect in an
 image.
 
 *Test data*: use chess_test\*.jpg images from your data folder.
 
--   Create an empty console project. Load a test image: :
+-   Create an empty console project. Load a test image :
 
         Mat img = imread(argv[1], IMREAD_GRAYSCALE);
 
--   Detect a chessboard in this image using findChessboard function. :
+-   Detect a chessboard in this image using findChessboard function :
 
         bool found = findChessboardCorners( img, boardSize, ptvec, CALIB_CB_ADAPTIVE_THRESH );
 
 -   Now, write a function that generates a vector\<Point3f\> array of 3d coordinates of a chessboard
     in any coordinate system. For simplicity, let us choose a system such that one of the chessboard
-    corners is in the origin and the board is in the plane *z = 0*.
+    corners is in the origin and the board is in the plane *z = 0*
 
--   Read camera parameters from XML/YAML file: :
+-   Read camera parameters from XML/YAML file :
 
-        FileStorage fs(filename, FileStorage::READ);
+        FileStorage fs( filename, FileStorage::READ );
         Mat intrinsics, distortion;
         fs["camera_matrix"] >> intrinsics;
         fs["distortion_coefficients"] >> distortion;
 
--   Now we are ready to find chessboard pose by running \`solvePnP\`: :
+-   Now we are ready to find a chessboard pose by running \`solvePnP\` :
 
         vector<Point3f> boardPoints;
         // fill the array
@@ -51,4 +51,5 @@ image.
 -   Calculate reprojection error like it is done in calibration sample (see
     opencv/samples/cpp/calibration.cpp, function computeReprojectionErrors).
 
-Question: how to calculate the distance from the camera origin to any of the corners?
+Question: how would you calculate distance from the camera origin to any one of the corners?
+Answer: As our image lies in a 3D space, firstly we would calculate the relative camera pose. This would give us 3D to 2D correspondences. Next, we can apply a simple L2 norm to calculate distance between any point (end point for corners).

doc/tutorials/calib3d/table_of_content_calib3d.markdown

 Camera calibration and 3D reconstruction (calib3d module) {#tutorial_table_of_content_calib3d}
 ==========================================================
 
-Although we got most of our images in a 2D format they do come from a 3D world. Here you will learn
-how to find out from the 2D images information about the 3D world.
+Although we get most of our images in a 2D format they do come from a 3D world. Here you will learn how to find out 3D world information from 2D images.
 
 -   @subpage tutorial_camera_calibration_square_chess
 

doc/tutorials/highgui/trackbar/trackbar.markdown

@@ -68,7 +68,7 @@ Result
     ![](images/Adding_Trackbars_Tutorial_Result_0.jpg)
 
 -   As a manner of practice, you can also add two trackbars for the program made in
-    @ref tutorial_basic_linear_transform. One trackbar to set \f$\alpha\f$ and another for \f$\beta\f$. The output might
+    @ref tutorial_basic_linear_transform. One trackbar to set \f$\alpha\f$ and another for set \f$\beta\f$. The output might
     look like:
 
     ![](images/Adding_Trackbars_Tutorial_Result_1.jpg)

doc/tutorials/imgproc/erosion_dilatation/erosion_dilatation.markdown

@@ -6,12 +6,12 @@ Goal
 
 In this tutorial you will learn how to:
 
--   Apply two very common morphology operators: Dilation and Erosion. For this purpose, you will use
+-   Apply two very common morphological operators: Erosion and Dilation. For this purpose, you will use
     the following OpenCV functions:
     -   @ref cv::erode
     -   @ref cv::dilate
 
-Cool Theory
+Interesting fact
 -----------
 
 @note The explanation below belongs to the book **Learning OpenCV** by Bradski and Kaehler.
@@ -21,7 +21,7 @@ Morphological Operations
 
 -   In short: A set of operations that process images based on shapes. Morphological operations
     apply a *structuring element* to an input image and generate an output image.
--   The most basic morphological operations are two: Erosion and Dilation. They have a wide array of
+-   The most basic morphological operations are: Erosion and Dilation. They have a wide array of
     uses, i.e. :
     -   Removing noise
     -   Isolation of individual elements and joining disparate elements in an image.
@@ -32,19 +32,19 @@ Morphological Operations
 
 ### Dilation
 
--   This operations consists of convoluting an image \f$A\f$ with some kernel (\f$B\f$), which can have any
+-   This operations consists of convolving an image \f$A\f$ with some kernel (\f$B\f$), which can have any
     shape or size, usually a square or circle.
 -   The kernel \f$B\f$ has a defined *anchor point*, usually being the center of the kernel.
 -   As the kernel \f$B\f$ is scanned over the image, we compute the maximal pixel value overlapped by
     \f$B\f$ and replace the image pixel in the anchor point position with that maximal value. As you can
     deduce, this maximizing operation causes bright regions within an image to "grow" (therefore the
-    name *dilation*). Take as an example the image above. Applying dilation we can get:
+    name *dilation*). Take the above image as an example. Applying dilation we can get:
 
     ![](images/Morphology_1_Tutorial_Theory_Dilation.png)
 
 The background (bright) dilates around the black regions of the letter.
 
-To better grasp the idea and avoid possible confusion, in this another example we have inverted the original
+To better grasp the idea and avoid possible confusion, in this other example we have inverted the original
 image such as the object in white is now the letter. We have performed two dilatations with a rectangular
 structuring element of size `3x3`.
 
@@ -54,8 +54,8 @@ The dilatation makes the object in white bigger.
 
 ### Erosion
 
--   This operation is the sister of dilation. What this does is to compute a local minimum over the
-    area of the kernel.
+-   This operation is the sister of dilation. It computes a local minimum over the
+    area of given kernel.
 -   As the kernel \f$B\f$ is scanned over the image, we compute the minimal pixel value overlapped by
     \f$B\f$ and replace the image pixel under the anchor point with that minimal value.
 -   Analagously to the example for dilation, we can apply the erosion operator to the original image
@@ -64,7 +64,7 @@ The dilatation makes the object in white bigger.
 
     ![](images/Morphology_1_Tutorial_Theory_Erosion.png)
 
-In the same manner, the corresponding image resulting of the erosion operation on the inverted original image (two erosions
+In similar manner, the corresponding image results by applying erosion operation on the inverted original image (two erosions
 with a rectangular structuring element of size `3x3`):
 
 ![Left image: original image inverted, right image: resulting erosion](images/Morphology_1_Tutorial_Theory_Erosion_2.png)
@@ -74,14 +74,14 @@ The erosion makes the object in white smaller.
 Code
 ----
 
-This tutorial code's is shown lines below. You can also download it from
+This tutorial's code is shown below. You can also download it
 [here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/ImgProc/Morphology_1.cpp)
 @include samples/cpp/tutorial_code/ImgProc/Morphology_1.cpp
 
 Explanation
 -----------
 
--#  Most of the stuff shown is known by you (if you have any doubt, please refer to the tutorials in
+-#  Most of the material shown here is trivial (if you have any doubt, please refer to the tutorials in
     previous sections). Let's check the general structure of the program:
 
     -   Load an image (can be BGR or grayscale)
@@ -118,8 +118,8 @@ Explanation
 
     -   That is all. We are ready to perform the erosion of our image.
 @note Additionally, there is another parameter that allows you to perform multiple erosions
-(iterations) at once. We are not using it in this simple tutorial, though. You can check out the
-Reference for more details.
+(iterations) at once. However, We haven't used it in this simple tutorial. You can check out the
+reference for more details.
 
 -#  **dilation:**
 

doc/tutorials/imgproc/imgtrans/warp_affine/warp_affine.markdown

@@ -14,9 +14,9 @@ Theory
 
 ### What is an Affine Transformation?
 
--#  It is any transformation that can be expressed in the form of a *matrix multiplication* (linear
+-#  A transformation that can be expressed in the form of a *matrix multiplication* (linear
     transformation) followed by a *vector addition* (translation).
--#  From the above, We can use an Affine Transformation to express:
+-#  From the above, we can use an Affine Transformation to express:
 
     -#  Rotations (linear transformation)
     -#  Translations (vector addition)
@@ -25,7 +25,7 @@ Theory
     you can see that, in essence, an Affine Transformation represents a **relation** between two
     images.
 
--#  The usual way to represent an Affine Transform is by using a \f$2 \times 3\f$ matrix.
+-#  The usual way to represent an Affine Transformation is by using a \f$2 \times 3\f$ matrix.
 
     \f[
     A = \begin{bmatrix}
@@ -49,7 +49,7 @@ Theory
    \f]
 
     Considering that we want to transform a 2D vector \f$X = \begin{bmatrix}x \\ y\end{bmatrix}\f$ by
-    using \f$A\f$ and \f$B\f$, we can do it equivalently with:
+    using \f$A\f$ and \f$B\f$, we can do the same with:
 
     \f$T = A \cdot \begin{bmatrix}x \\ y\end{bmatrix} + B\f$ or \f$T = M \cdot  [x, y, 1]^{T}\f$
 
@@ -60,35 +60,35 @@ Theory
 
 ### How do we get an Affine Transformation?
 
--#  Excellent question. We mentioned that an Affine Transformation is basically a **relation**
+-#  We mentioned that an Affine Transformation is basically a **relation**
     between two images. The information about this relation can come, roughly, in two ways:
-    -#  We know both \f$X\f$ and T and we also know that they are related. Then our job is to find \f$M\f$
+    -#  We know both \f$X\f$ and T and we also know that they are related. Then our task is to find \f$M\f$
     -#  We know \f$M\f$ and \f$X\f$. To obtain \f$T\f$ we only need to apply \f$T = M \cdot X\f$. Our information
         for \f$M\f$ may be explicit (i.e. have the 2-by-3 matrix) or it can come as a geometric relation
         between points.
 
--#  Let's explain a little bit better (b). Since \f$M\f$ relates 02 images, we can analyze the simplest
+-#  Let's explain this in a better way (b). Since \f$M\f$ relates 2 images, we can analyze the simplest
     case in which it relates three points in both images. Look at the figure below:
 
     ![](images/Warp_Affine_Tutorial_Theory_0.jpg)
 
     the points 1, 2 and 3 (forming a triangle in image 1) are mapped into image 2, still forming a
     triangle, but now they have changed notoriously. If we find the Affine Transformation with these
-    3 points (you can choose them as you like), then we can apply this found relation to the whole
-    pixels in the image.
+    3 points (you can choose them as you like), then we can apply this found relation to all the
+    pixels in an image.
 
 Code
 ----
 
 -#  **What does this program do?**
     -   Loads an image
-    -   Applies an Affine Transform to the image. This Transform is obtained from the relation
+    -   Applies an Affine Transform to the image. This transform is obtained from the relation
         between three points. We use the function @ref cv::warpAffine for that purpose.
     -   Applies a Rotation to the image after being transformed. This rotation is with respect to
         the image center
     -   Waits until the user exits the program
 
--#  The tutorial code's is shown lines below. You can also download it from
+-#  The tutorial's code is shown below. You can also download it here
     [here](https://github.com/opencv/opencv/tree/master/samples/cpp/tutorial_code/ImgTrans/Geometric_Transforms_Demo.cpp)
     @include samples/cpp/tutorial_code/ImgTrans/Geometric_Transforms_Demo.cpp
 
@@ -113,10 +113,10 @@ Explanation
     @code{.cpp}
     warp_dst = Mat::zeros( src.rows, src.cols, src.type() );
     @endcode
--#  **Affine Transform:** As we explained lines above, we need two sets of 3 points to derive the
-    affine transform relation. Take a look:
+-#  **Affine Transform:** As we explained in lines above, we need two sets of 3 points to derive the
+    affine transform relation. Have a look:
     @code{.cpp}
-    srcTri[0] = Point2f( 0,0 );
+    srcTri[0] = Point2f( 0, 0 );
     srcTri[1] = Point2f( src.cols - 1, 0 );
     srcTri[2] = Point2f( 0, src.rows - 1 );
 
@@ -124,7 +124,7 @@ Explanation
     dstTri[1] = Point2f( src.cols*0.85, src.rows*0.25 );
     dstTri[2] = Point2f( src.cols*0.15, src.rows*0.7 );
     @endcode
-    You may want to draw the points to make a better idea of how they change. Their locations are
+    You may want to draw these points to get a better idea on how they change. Their locations are
     approximately the same as the ones depicted in the example figure (in the Theory section). You
     may note that the size and orientation of the triangle defined by the 3 points change.
 
@@ -133,9 +133,9 @@ Explanation
     @code{.cpp}
     warp_mat = getAffineTransform( srcTri, dstTri );
     @endcode
-    We get as an output a \f$2 \times 3\f$ matrix (in this case **warp_mat**)
+    We get a \f$2 \times 3\f$ matrix as an output (in this case **warp_mat**)
 
--#  We apply the Affine Transform just found to the src image
+-#  We then apply the Affine Transform just found to the src image
     @code{.cpp}
     warpAffine( src, warp_dst, warp_mat, warp_dst.size() );
     @endcode

doc/tutorials/imgproc/table_of_content_imgproc.markdown

@@ -41,7 +41,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Theodore Tsesmelis
 
-    Here we will show how we can use different morphology operators to extract horizontal and vertical lines
+    Here we will show how we can use different morphological operators to extract horizontal and vertical lines
 
 -   @subpage tutorial_pyramids
 
@@ -57,7 +57,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    After so much processing, it is time to decide which pixels stay!
+    After so much processing, it is time to decide which pixels stay
 
 -   @subpage tutorial_threshold_inRange
 
@@ -81,7 +81,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn how to pad our images!
+    Where we learn how to pad our images
 
 -   @subpage tutorial_sobel_derivatives
 
@@ -89,7 +89,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn how to calculate gradients and use them to detect edges!
+    Where we learn how to calculate gradients and use them to detect edges
 
 -   @subpage tutorial_laplace_operator
 
@@ -97,7 +97,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn about the *Laplace* operator and how to detect edges with it.
+    Where we learn about the *Laplace* operator and how to detect edges with it
 
 -   @subpage tutorial_canny_detector
 
@@ -105,7 +105,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn a sophisticated alternative to detect edges.
+    Where we learn a sophisticated alternative to detect edges
 
 -   @subpage tutorial_hough_lines
 
@@ -193,7 +193,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn how to get hull contours and draw them!
+    Where we learn how to get hull contours and draw them
 
 -   @subpage tutorial_bounding_rects_circles
 
@@ -201,7 +201,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn how to obtain bounding boxes and circles for our contours.
+    Where we learn how to obtain bounding boxes and circles for our contours
 
 -   @subpage tutorial_bounding_rotated_ellipses
 
@@ -209,7 +209,7 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Ana Huamán
 
-    Where we learn how to obtain rotated bounding boxes and ellipses for our contours.
+    Where we learn how to obtain rotated bounding boxes and ellipses for our contours
 
 -   @subpage tutorial_moments
 
@@ -233,4 +233,4 @@ In this section you will learn about the image processing (manipulation) functio
 
     *Author:* Theodore Tsesmelis
 
-    Where we learn to segment objects using Laplacian filtering, the Distance Transformation and the Watershed algorithm.
\ No newline at end of file
+    Where we learn to segment objects using Laplacian filtering, the Distance Transformation and the Watershed algorithm.

doc/tutorials/introduction/linux_install/linux_install.markdown

 Installation in Linux {#tutorial_linux_install}
 =====================
 
-These steps have been tested for Ubuntu 10.04 but should work with other distros as well.
+The following steps have been tested for Ubuntu 10.04 but should work with other distros as well.
 
 Required Packages
 -----------------
@@ -39,7 +39,7 @@ repository](https://github.com/opencv/opencv.git).
 ### Getting the Cutting-edge OpenCV from the Git Repository
 
 Launch Git client and clone [OpenCV repository](http://github.com/opencv/opencv). If you need
-modules from [OpenCV contrib repository](http://github.com/opencv/opencv_contrib) then clone it too.
+modules from [OpenCV contrib repository](http://github.com/opencv/opencv_contrib) then clone it as well.
 
 For example
 @code{.bash}
@@ -97,7 +97,7 @@ Building OpenCV from Source Using CMake
     -   It is useful also to unset BUILD_EXAMPLES, BUILD_TESTS, BUILD_PERF_TESTS - as they all
         will be statically linked with OpenCV and can take a lot of memory.
 
--#  Build. From build directory execute make, recomend to do it in several threads
+-#  Build. From build directory execute *make*, it is recommended to do this in several threads
 
     For example
     @code{.bash}
@@ -111,7 +111,7 @@ Building OpenCV from Source Using CMake
     cd ~/opencv/build/doc/
     make -j7 html_docs
     @endcode
--#  To install libraries, from build directory execute
+-#  To install libraries, execute the following command from build directory
     @code{.bash}
     sudo make install
     @endcode
@@ -134,6 +134,6 @@ Building OpenCV from Source Using CMake
 
 @note
    If the size of the created library is a critical issue (like in case of an Android build) you
-    can use the install/strip command to get the smallest size as possible. The *stripped* version
+    can use the install/strip command to get the smallest size possible. The *stripped* version
     appears to be twice as small. However, we do not recommend using this unless those extra
     megabytes do really matter.

doc/tutorials/tutorials.markdown

@@ -2,7 +2,7 @@ OpenCV Tutorials {#tutorial_root}
 ================
 
 The following links describe a set of basic OpenCV tutorials. All the source code mentioned here is
-provided as part of the OpenCV regular releases, so check before you start copy & pasting the code.
+provided as part of the OpenCV regular releases, so check before you start copying & pasting the code.
 The list of tutorials below is automatically generated from reST files located in our GIT
 repository.
 
@@ -10,12 +10,12 @@ As always, we would be happy to hear your comments and receive your contribution
 
 -   @subpage tutorial_table_of_content_introduction
 
-    You will learn how to setup OpenCV on your computer!
+    You will learn how to setup OpenCV on your computer
 
 -   @subpage tutorial_table_of_content_core
 
     Here you will learn
-    the about the basic building blocks of the library. A must read and know for understanding how
+    the about the basic building blocks of this library. A must read for understanding how
     to manipulate the images on a pixel level.
 
 -   @subpage tutorial_table_of_content_imgproc
@@ -25,7 +25,7 @@ As always, we would be happy to hear your comments and receive your contribution
 
 -   @subpage tutorial_table_of_content_highgui
 
-    This section contains valuable tutorials about how to use the
+    This section contains valuable tutorials on how to use the
     built-in graphical user interface of the library.
 
 -   @subpage tutorial_table_of_content_imgcodecs
@@ -38,9 +38,9 @@ As always, we would be happy to hear your comments and receive your contribution
 
 -   @subpage tutorial_table_of_content_calib3d
 
-    Although we got
-    most of our images in a 2D format they do come from a 3D world. Here you will learn how to find
-    out from the 2D images information about the 3D world.
+    Although
+    most of our images are in a 2D format they do come from a 3D world. Here you will learn how to find
+    out 3D world information from 2D images.
 
 -   @subpage tutorial_table_of_content_features2d
 
@@ -49,14 +49,14 @@ As always, we would be happy to hear your comments and receive your contribution
 
 -   @subpage tutorial_table_of_content_video
 
-    Look here in order
-    to find algorithms usable on your video streams like: motion extraction, feature tracking and
+    Here you will find
+    algorithms usable on your video streams like motion extraction, feature tracking and
     foreground extractions.
 
 -   @subpage tutorial_table_of_content_objdetect
 
     Ever wondered
-    how your digital camera detects peoples and faces? Look here to find out!
+    how your digital camera detects people's faces? Look here to find out!
 
 -   @subpage tutorial_table_of_content_ml
 
@@ -75,7 +75,7 @@ As always, we would be happy to hear your comments and receive your contribution
 -   @subpage tutorial_table_of_content_gpu
 
     Squeeze out every
-    little computation power from your system by using the power of your video card to run the
+    little computational power from your system by utilizing the power of your video card to run the
     OpenCV algorithms.
 
 -   @subpage tutorial_table_of_content_ios