Cfrgtkky

Here is my MWE:

documentclass{standalone}

usepackage{graphicx, lipsum}

usepackage[most]{tcolorbox}



newtcolorbox{myminipage}[3]{

    breakable,

    blankest, 

    watermark graphics=#3, 

    watermark stretch=1,

    width=#2,

    #1

}



begin{document}



begin{myminipage}{3cm}{example-image}

lipsum[2]

end{myminipage}



end{document}

This is taken from here.

The background image scales. Can it be cropped, instead?

And lastly, will it be possible to produce a jpeg or png directly?

Are you looking for the standalone class with the varwidth option?

documentclass[varwidth]{standalone}

usepackage{ eso-pic,tikz, lipsum}

usetikzlibrary{tikzmark}

linespread{2}

newcommandBackgroundPic{%

begin{tikzpicture}[overlay,remember picture]

node[anchor=north west,inner sep=0pt] at ([yshift=8pt]pic cs:start) {%

includegraphics[width=textwidth]{example-image}};

end{tikzpicture}}



begin{document}

AddToShipoutPicture*{BackgroundPic}



tikzmark{start}lipsum[1-1]



end{document}

OLDER VERSIONS: tikzpagenodes allows you to precisely determined the text area.

documentclass{article}

usepackage{geometry, eso-pic, tikzpagenodes, lipsum}

linespread{2}

newcommandBackgroundPic{%

begin{tikzpicture}[overlay,remember picture]

node[anchor=north west,inner sep=0pt] at (current page text area.north west) {

includegraphics[width=textwidth,height=textheight,%

]{example-image}};

end{tikzpicture}}

geometry{

  a4paper, 

  portrait, 

  margin=1in, 

  top=.25in, 

  bottom=1.75in

}



begin{document}

AddToShipoutPicture*{BackgroundPic}

thispagestyle{empty}



lipsum[1-1]



end{document}

Here is something that crops the image against the text...

documentclass{article}

usepackage{geometry, eso-pic, tikzpagenodes, lipsum}

usetikzlibrary{tikzmark}

linespread{2}

newcommandBackgroundPic{%

begin{tikzpicture}[overlay,remember picture]

path ([yshift=12pt]pic cs:start) coordinate(aux1) ([yshift=-3pt]pic cs:end) coordinate(aux2);

clip (current page text area.west |-aux1) rectangle

(current page text area.east |-aux2);

node[anchor=north west,inner sep=0pt] at (current page text area.north west) {%

includegraphics[width=textwidth]{example-image}};

end{tikzpicture}}

geometry{

  a4paper, 

  portrait, 

  margin=1in, 

  top=.25in, 

  bottom=1.75in

}



begin{document}

AddToShipoutPicture*{BackgroundPic}

thispagestyle{empty}



tikzmark{start}lipsum[1-1]tikzmark{end}



end{document}