metapixel-helper to gather images and sort them via metapixel-sizesort and afterwards use prepare them via metapixel-prepare with appropriate aspect ratios

gatherimages.sh

#!/bin/zsh

convert=/usr/bin/convert

metapixelsizesort=/usr/bin/metapixel-sizesort

dir=$1
targetdir=$2

root=`pwd`

mkdir -p ${targetdir}/gathering
mkdir ${targetdir}/sizesort

for i in ${dir}/**/*.jpg
do
  MD5i=`echo "$i" | md5sum | cut -d ' ' -f 1`
  echo "$convert \"$i\" $convertopts \"${targetdir}/${MD5i}.jpg\""
  $convert "$i" -auto-orient -resize 710 "${targetdir}/gathering/${MD5i}.jpg"
done

$metapixelsizesort -r 2 ${targetdir}/gathering ${targetdir}/sizesort

prepareimages.sh

#!/bin/zsh

metapixelprepare=/usr/bin/metapixel-prepare

dir=$1
targetdir=$2

root=`pwd`

size=128

# Default scale used by float functions.
float_scale=2

#####################################################################
# Evaluate a floating point number expression.

function float_eval()
{
    local stat=0
    local result=0.0
    if [[ $# -gt 0 ]]; then
        result=$(echo "scale=$float_scale; $*" | bc -q 2>/dev/null)
        stat=$?
        if [[ $stat -eq 0  &&  -z "$result" ]]; then stat=1; fi
    fi
    echo $result
    return $stat
}

# Evaluate a floating point number conditional expression.

function float_cond()
{
    local cond=0
    if [[ $# -gt 0 ]]; then
        cond=$(echo "$*" | bc -q 2>/dev/null)
        if [[ -z "$cond" ]]; then cond=0; fi
        if [[ "$cond" != 0  &&  "$cond" != 1 ]]; then cond=0; fi
    fi
    local stat=$((cond == 0))
    return $stat
}




mkdir ${targetdir}

for i in ${dir}/sizesort/ratio_*
do
  current_ratio=`echo "$i" | cut -d "_" -f 2`
  vart=$(float_eval "$current_ratio + 2")
  
  if float_cond "$current_ratio < 1.0"; then
    thisheight=$(float_eval "($size / $current_ratio) - 0.5")
    thiswidth=$size
    thisheight=${thisheight/.*}
  else
    thisheight=$size
    set -f
    thiswidth=$(float_eval "($size * $current_ratio) - 0.5")
    thiswidth=${thiswidth/.*}
    set +f
  fi

  echo "$metapixelprepare -r --height=$thisheight --width=$thiswidth ${i} ${targetdir}"
  $metapixelprepare -r --height=$thisheight --width=$thiswidth ${i} ${targetdir}
done