fixed xcolor warnings when building opencv_tutorials.pdf

doc/conf.py

@@ -170,7 +170,7 @@ htmlhelp_basename = 'opencv'
 
 # OpenCV docs use some custom LaTeX macros in the formula. Make sure we include the definitions
 pngmath_latex_preamble = r"""
-\usepackage{euler}\usepackage[usenames,dvipsnames]{color}\usepackage{amssymb}\usepackage{amsmath}\usepackage{bbm}\usepackage[table]{xcolor}
+\usepackage{euler}\usepackage[usenames,dvipsnames]{color}\usepackage{amssymb}\usepackage{amsmath}\usepackage{bbm}\usepackage{colortbl}
 \newcommand{\matTT}[9]{
 \[
 \left|\begin{array}{ccc}
@@ -235,7 +235,7 @@ preamble ="""
 \usepackage{euler}
 \usepackage[scaled=0.85]{beramono}
 \usepackage{mymath}\usepackage{amssymb}\usepackage{amsmath}\usepackage{bbm}\setcounter{secnumdepth}{1}
-\usepackage[table]{xcolor}
+\usepackage{colortbl}
 """
 
 latex_elements = {'preamble': preamble}

doc/tutorials/core/how_to_scan_images/how_to_scan_images.rst

@@ -65,7 +65,7 @@ As you could already read in my :ref:`matTheBasicImageContainer` tutorial the si
 
 .. math::
 
-   \newcommand{\tabItG}[1] { \textcolor{black}{#1} \cellcolor{gray}}
+   \newcommand{\tabItG}[1] { \textcolor{black}{#1} \cellcolor[gray]{0.8}}
    \begin{tabular} {ccccc}
    ~ & \multicolumn{1}{c}{Column 0} &   \multicolumn{1}{c}{Column 1} &   \multicolumn{1}{c}{Column ...} & \multicolumn{1}{c}{Column m}\\
    Row 0 & \tabItG{0,0} & \tabItG{0,1} & \tabItG{...}  & \tabItG{0, m} \\