img-url-exif.sh

img-url-exif.sh

#!/usr/bin/env bash

# Josh Skidmore <[email protected]>

# Basic example of using an HTTP range header to extract EXIF data
# from a JPEG file without having to download the entire image.
# This has no error handling and assumes the EXIF data is embedded
# within the first $KB_TO_DOWNLOAD kilobytes of the image
# Requirements:
#   * curl
#   * exiftool

# Example JPEGs:
# https://raw.githubusercontent.com/ianare/exif-samples/master/jpg/Ricoh_Caplio_RR330.jpg
# https://live.staticflickr.com/3866/14356072311_4ef21a1001_o_d.jpg


[[ -z "$1" ]] && \
  echo "Usage: $(basename $0) [JPEG_URL]" && \
  exit

IMG_URL=$1
KB_TO_DOWNLOAD=100
B_TO_DOWNLOAD=$((KB_TO_DOWNLOAD*1024))
TMP_DIR=$(mktemp -d)
TMP_IMG=$TMP_DIR/temp.jpg
THU_IMG=$TMP_DIR/thumbnail.jpg
EXIF_DUMP_FILE=$TMP_DIR/exif.txt

# grab the image with a range query
curl -s -o $TMP_IMG --header "Range: bytes=0-${B_TO_DOWNLOAD}" $IMG_URL

# (debugging) determine exif starting byte range
exif_starting_byte=$(cat $TMP_IMG | grep -a -bo Exif | cut -d : -f 1)

# extract exif data
exif_data=$(exiftool $TMP_IMG)

# dump exif to file
echo -e "$exif_data" > $EXIF_DUMP_FILE

# dump exif to console
echo "#### START EXIF ####"
echo -e "$exif_data"
echo "#### END EXIF ####"

echo

echo "Image URL: $IMG_URL"
echo "Bytes Transferred: $B_TO_DOWNLOAD"
echo "EXIF Starting Marker Byte: $exif_starting_byte"
echo "EXIF Dump: $EXIF_DUMP_FILE"

# if an exif thumbnail is available, extract
[[ "$exif_data" =~ Thumbnail ]] && \
  exiftool -b -ThumbnailImage $TMP_IMG > $THU_IMG && \
  echo "Extracted Thumbnail: $THU_IMG"