tikz com autônomo tem borda à esquerda

Question

Sempre acho que o autônomo centralizará minha imagem. mas o exemplo abaixo não:

\documentclass[border=1mm]{standalone}
\usepackage{tikz}
\usepackage{graphicx}
\usepackage{calc}
\usepackage{ifthen}
\usetikzlibrary{backgrounds}

\begin{document}
%jpg from http://www.murderousmaths.co.uk/magic/predictor%20cards%20template%20120.jpg
\def\infilename{/Users/e12714/Downloads/a.jpg}

\newsavebox{\graph}\savebox{\graph}{\includegraphics{\infilename}}
\newlength\gh\setlength\gh{\heightof{\usebox\graph}}
\newlength\gw\setlength\gw{\widthof{\usebox\graph}}

\newcounter{DEBUG}
\setcounter{DEBUG}{1}
\setcounter{DEBUG}{0}

\def\BL{0.16\gw,0.106\gh} % bottom left corner
\def\TR{0.92\gw,0.86\gh} % top right corner

\begin{tikzpicture}[framed,>=latex,
  image/.style={anchor=south west,inner sep=0,outer sep=0}]
    \ifthenelse{\theDEBUG = 1}{   
        % do nothing for debug purpose
    }{
        \clip (\BL) rectangle (\TR);
    }
   \node[image] (NI) {\usebox\graph};
   \ifthenelse{\theDEBUG = 1}{
        \draw[red,line width=2pt] (\BL) rectangle (\TR);
        \begin{scope}[x={(NI.south east)},y={(NI.north west)}]
            \draw[help lines,xstep=.1,ystep=.1] (0,0) grid (1.001,1.001);
            \foreach \x in {1,...,9} { \node [anchor=north] at (\x/10,0) {\x};}
            \foreach \y in {1,...,9} { \node [anchor=east] at (0,\y/10) {\y};}
        \end{scope}
    }{}
\end{tikzpicture}

\end{document}

Por que ainda há uma barra branca à esquerda da imagem recortada?

Answer 1

Isso acontece porque existem parágrafos e outros espaços em branco antes da imagem real.

Se você mover \begin{document}para a direita antes de \begin{tikzpicture}, o problema desaparecerá porque o espaço em branco será ignorado no preâmbulo.

\documentclass[border=1mm]{standalone}
\usepackage{tikz}
\usepackage{graphicx}
\usepackage{calc}
\usepackage{ifthen}
\usetikzlibrary{backgrounds}

%jpg from http://www.murderousmaths.co.uk/magic/predictor%20cards%20template%20120.jpg
\def\infilename{example-image}

\newsavebox{\graph}\savebox{\graph}{\includegraphics{\infilename}}
\newlength\gh\setlength\gh{\heightof{\usebox\graph}}
\newlength\gw\setlength\gw{\widthof{\usebox\graph}}

\newcounter{DEBUG}
\setcounter{DEBUG}{1}
\setcounter{DEBUG}{0}

\def\BL{0.16\gw,0.106\gh} % bottom left corner
\def\TR{0.92\gw,0.86\gh} % top right corner

\begin{document}
\begin{tikzpicture}[framed,>=latex,
  image/.style={anchor=south west,inner sep=0,outer sep=0}]
    \ifthenelse{\theDEBUG = 1}{   
        % do nothing for debug purpose
    }{
        \clip (\BL) rectangle (\TR);
    }
   \node[image] (NI) {\usebox\graph};
   \ifthenelse{\theDEBUG = 1}{
        \draw[red,line width=2pt] (\BL) rectangle (\TR);
        \begin{scope}[x={(NI.south east)},y={(NI.north west)}]
            \draw[help lines,xstep=.1,ystep=.1] (0,0) grid (1.001,1.001);
            \foreach \x in {1,...,9} { \node [anchor=north] at (\x/10,0) {\x};}
            \foreach \y in {1,...,9} { \node [anchor=east] at (0,\y/10) {\y};}
        \end{scope}
    }{}
\end{tikzpicture}
\end{document}

Alternativamente, você poderia colocar %sinais nas linhas vazias e nos finais das linhas que causam problemas, mas neste caso não é necessário.