ImageMagick displayコマンドによる画像の縮小拡大表示とスクリーン上の表示位置指定

2022 Jan. 23.

参考ページ　(HobNote)ImageMagick option

"-resize"で画像を縮小拡大し、"-geometry"で表示キャンバスの大きさとスクリーン上の位置を指定する。

display -resize WIDTHxHIGHT -geometry WIDTHxHIGHT+OffsetWidth+OffsetHight PictureFile

Sample

# get screen resolution
ScreenX=$(xdpyinfo | grep dimensions  | grep -Po -m 1 "[0-9]+x" | head -n 1)
ScreenX=${ScreenX%x}

ScreenY=$(xdpyinfo | grep dimensions  | grep -Po -m 1 "x[0-9]+" | head -n 1)
ScreenY=${ScreenY#x}

# set display size
DisplayX=$(( ${ScreenX} * ${Size} / 100 ))
DisplayY=$(( ${ScreenY} * ${Size} / 100 ))

  # SIZE: ratio to screen-resolution.
  #   Unit of SIZE is %.(Integer in 0-100)
  #   Display-size of picture is SIZE(%) of screen-resolution.

# get location of picture in screen
case "${Loc}" in
  # Loc indicates area of screen in which picture is displayed.
  nw) # North West
    Geomet="${DisplayX}x${DisplayY}+0+0"
    ;;
  ne) # North East
    OffX=$(( ${ScreenX} - ${DisplayX} )) 
    Geomet="${DisplayX}x${DisplayY}+${OffX}+0"
    ;;
  sw) # South West
    OffY=$(( ${ScreenY} - ${DisplayY} )) 
    Geomet="${DisplayX}x${DisplayY}+0+${OffY}"
    ;;
  se) # South East
    OffX=$(( ${ScreenX} - ${DisplayX} )) 
    OffY=$(( ${ScreenY} - ${DisplayY} )) 
    Geomet="${DisplayX}x${DisplayY}+${OffX}+${OffY}"
    ;;
  ce) # Center
    OffX=$(( ${ScreenX} / 2 - ( ${DisplayX} / 2) )) 
    OffY=$(( ${ScreenY} / 2 - ( ${DisplayY} / 2) )) 
    Geomet="${DisplayX}x${DisplayY}+${OffX}+${OffY}"
    ;;
  *)
    echo "Illegal value for location." 1>&2
    exit 1
    ;;
esac

display -resize "${DisplayX}x${DisplayY}" -geometry "${Geomet}" PictureFile