+#!/bin/bash
+# Desc: Analyzes photo files selected in gThumb; shows size/time/GPS
+# statistics in a zenity dialog. Intended for evaluating burst-mode
+# sequences where larger JPEG size correlates with sharpness.
+# Usage: gthumb-analyze.sh FILE…
+# Example: $HOME/.local/bin/gthumb-analyze.sh %F
+# Depends: bash, GNU coreutils, awk, bc, column (util-linux 2.39.3)
+# exiftool (12.x), GNU sed 4.9, zenity
+# Version: 0.0.9
+
+fdebug=/tmp/gtAnalyzeLog.txt;
+
+yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
+die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
+must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
+main() {
+ # Validate inputs
+ local fina fin cmd;
+ fina=("$@");
+ if [[ $# -le 0 ]]; then die "FATAL:No arguments:$#"; fi;
+ for fin in "${fina[@]}"; do
+ if [[ ! -f "$fin" ]]; then die "FATAL:Not a file:${fin}"; fi;
+ done;
+ for cmd in awk bc column cut exiftool sed sort zenity; do
+ command -v "$cmd" >/dev/null 2>&1 || die "FATAL:Missing dependency:${cmd}";
+ done;
+
+ # Single batched exiftool pass. Columns (tab-separated):
+ # col 1: FileName
+ # col 2: FileSize [bytes]
+ # col 3: SubSecCreateDate [float POSIX seconds]
+ # col 4: GPSPosition [±Lat, ±Lon]
+ # col 5: FNumber [float]
+ # col 6: ExposureTime [str seconds]
+ # col 7: ISO [int]
+ # col 8: FocalLength [str %.01f mm]
+ # Note: Missing tags emit '-' in -T mode.
+ local tsv;
+ tsv="$(exiftool -q -T -FileName '-FileSize#' \
+ -SubSecCreateDate -d '%s%f' \
+ -GPSPosition -c '%+0.4f' \
+ -FNumber -ExposureTime -ISO -FocalLength \
+ -- "${fina[@]}")" \
+ || die "FATAL:exiftool failed";
+ yell "DEBUG:tsv:"; printf '%s\n' "$tsv" 1>&2;
+
+ local n fMax fMaxArr fMin fMinArr mean sdev median span gps;
+ n="$(printf '%s\n' "$tsv" | wc -l)";
+
+ # First and last by file name
+ local fFirst fLast;
+ fFirst="$(printf '%s\n' "$tsv" | sort -t$'\t' -k1,1 | head -n1 | cut -f1)";
+ fLast="$(printf '%s\n' "$tsv" | sort -t$'\t' -k1,1 | tail -n1 | cut -f1)";
+
+ # Largest and smallest files by size (numeric sort on column 2)
+ fMax="$(printf '%s\n' "$tsv" | sort -t$'\t' -k2,2n | tail -n1)";
+ fMin="$(printf '%s\n' "$tsv" | sort -t$'\t' -k2,2n | head -n1)";
+ fMaxArr[0]="$(cut -f1 <<< "$fMax")";
+ fMaxArr[1]="$(cut -f2 <<< "$fMax")";
+ fMinArr[0]="$(cut -f1 <<< "$fMin")";
+ fMinArr[1]="$(cut -f2 <<< "$fMin")";
+ ## Avoid & or < being parsed as markup by zenity
+ fMaxArr[0]="$(sed -e 's/&/\&/g' -e 's/</\</g' <<< "${fMaxArr[0]}")";
+ fMinArr[0]="$(sed -e 's/&/\&/g' -e 's/</\</g' <<< "${fMinArr[0]}")";
+
+ # Mean and population standard deviation (÷N, not N−1: the
+ # selection is the entire population of interest).
+ read -r mean sdev < <(printf '%s\n' "$tsv" | cut -f2 \
+ | awk '{s+=$1; ss+=$1*$1;} END {m=s/NR; printf "%.0f %.0f\n", m, sqrt(ss/NR - m*m);}');
+
+ # Median file size
+ median="$(printf '%s\n' "$tsv" | cut -f2 | sort -n \
+ | awk '{a[i++]=$1;} END {if (i%2==0) {printf "%.0f\n", (a[i/2-1]+a[i/2])/2;} else {print a[int(i/2)];};}')";
+
+ # Time span in seconds via bc; ignore files lacking dates.
+ local tMin tMax;
+ tMin="$(printf '%s\n' "$tsv" | cut -f3 | grep -v '^-$' | sort -n | head -n1)";
+ tMax="$(printf '%s\n' "$tsv" | cut -f3 | grep -v '^-$' | sort -n | tail -n1)";
+ if [[ -n "$tMin" && -n "$tMax" ]]; then
+ span="$(printf "%'.3f s" "$(bc -l <<< "${tMax} - ${tMin}")")"; # seconds
+ else
+ span="n/a (missing SubSecCreateDate)";
+ fi;
+
+ # GPS: single unique value, none, or multiple.
+ local gpsUniq gpsUniqSamp gpsCount;
+ gpsUniq="$(printf '%s\n' "$tsv" | cut -f4 | sort -u | grep -v '^-$')";
+ gpsCount="$(printf '%s\n' "$gpsUniq" | grep -c .)";
+ case "$gpsCount" in
+ 0) gps="none";;
+ *) gps="(${gpsCount} distinct)";
+ mapfile -t gpsUniqSamp < <(shuf <<< "$gpsUniq" | head -n8 | sort);;
+ esac;
+
+ # Exposure combos: unique (FNumber, ExposureTime, ISO, FocalLength) tuples.
+ # Missing tags appear as '-' and still compare consistently.
+ local expUniq expUniqSamp expCount exp;
+ expUniq="$(printf '%s\n' "$tsv" | cut -f5-8 | sort -u \
+ | awk -F'\t' '{printf "f/%s\t%s s\tISO %s\t%s\n", $1, $2, $3, $4;}')";
+ mapfile -t expUniqSamp < <(shuf <<< "$expUniq" | head -n8 | sort -t $'\t' -k4,4n);
+
+ expCount="$(printf '%s\n' "$expUniq" | grep -c .)";
+ case "$expCount" in
+ 1) exp="uniform";;
+ *) exp="${expCount} distinct combinations";;
+ esac;
+
+ # Report
+ local msgSec1Arr msgSec1 msgSec2Arr msgSec2 msgSec3Arr msgSec3 msg;
+ ## Assemble message section 1 (file size, time span)
+ msgSec1Arr+=("$(printf "%d files analyzed (About %d s)" "$n" "$SECONDS")");
+ msgSec1Arr+=("$(printf "First:\t\t%s" "$fFirst")");
+ msgSec1Arr+=("$(printf "Last:\t\t%s" "$fLast")");
+ msgSec1Arr+=("$(printf "%s" "----" )");
+ msgSec1Arr+=("$(printf "Largest:\t%'d B\t%s" "${fMaxArr[1]}" "${fMaxArr[0]}")");
+ msgSec1Arr+=("$(printf "Smallest:\t%'d B\t%s" "${fMinArr[1]}" "${fMinArr[0]}")");
+ msgSec1Arr+=("$(printf "Mean size:\t%'d B" "$mean")");
+ msgSec1Arr+=("$(printf "Median size:\t%'d B" "$median")");
+ msgSec1Arr+=("$(printf "Std. dev.:\t%'d B" "$sdev")");
+ msgSec1Arr+=("$(printf "Time span:\t%s" "$span")");
+ msgSec1="$(printf '%s\n' "${msgSec1Arr[@]}" | column -s $'\t' -t --table-right 2)";
+ ## Assemble message section 2 (location)
+ msgSec2Arr+=("$(printf "GPS:\t%s" "$gps")");
+ msgSec2Arr+=("$(printf '%s\n' "${gpsUniqSamp[@]}")");
+ msgSec2="$(printf '%s\n' "${msgSec2Arr[0]}"; printf '%s\n' "${msgSec2Arr[@]:1}" | column -s $'\t' -t | sed -e 's/^/\t/')";
+ ## Assemble message section 3 (exposure)
+ msgSec3Arr+=("$(printf "Exposure:\t%s" "$exp")");
+ msgSec3Arr+=("$(printf '%s\n' "${expUniqSamp[@]}")");
+ msgSec3="$(printf '%s\n' "${msgSec3Arr[0]}"; printf '%s\n' "${msgSec3Arr[@]:1}" | column -s $'\t' -t | sed -e 's/^/\t/')";
+ ## Assemble combined message
+ msg="$(printf '%s\n--------\n' "$msgSec1" "$msgSec2" "$msgSec3")";
+ ## Display message
+ zenity --info --title="gThumb-analyze.sh stats" --no-wrap --text="<span font='monospace'>${msg}</span>";
+};
+
+main "$@" 1>>"$fdebug" 2>&1;
+
+# Author: Steven Baltakatei Sandoval
+# License: GPLv3+
+