Set an image's metadata for panoramic viewing using a different image as reference.

sphere-metadata.py

#!/usr/bin/env python2

import re
import struct
import argparse
import StringIO
import pyexiv2 as pe
from pprint import PrettyPrinter
from os.path import abspath, isfile


def query_yes_no(question, default=None):
    """ Ask a yes/no question and return the answer.
    """
    valid = {'yes': True, 'y': True, 'no': False, 'n': False}
    prompt = '[y/n]'
    if default == 'yes':
        prompt = '[Y/n]'
    elif default == 'no':
        prompt = '[y/N]'

    while True:
        print(question + ' ' + prompt + ' ')
        c = raw_input().lower()
        if default is not None and c == '':
            return valid[default]
        elif c in valid:
            return valid[c]
        else:
            print("Please select a choice <[yes/y]|[no/n]>\n")


def to_deg(value, loc):
    if value < 0:
        loc_value = loc[0]
    elif value > 0:
        loc_value = loc[1]
    else:
        loc_value = ""
    abs_value = abs(value)
    deg = int(abs_value)
    t1 = (abs_value - deg) * 60
    min = int(t1)
    sec = round((t1 - min) * 60, 5)
    return (deg, min, sec, loc_value)


def show_meta(md):
    mdKeys = md.iptc_keys + md.exif_keys + md.xmp_keys
    print(19 * '=' + ' BEGIN METADATA ' + 19 * '=')
    try:
        maxLen = len(max(mdKeys, key=len))
        for k in mdKeys:
            v = md[k].value
            print('{}{}  =>  {}'.format(k, ' ' * (maxLen - len(k)), v))
    except:
        pass
    print(20 * '=' + ' END METADATA ' + 20 * '=')


def get_image_info(data):
    ''' http://stackoverflow.com/questions/1507084/how-to-check-dimensions-of-all-images-in-a-directory-using-python#answer-3175473
    '''
    data = str(data)
    size = len(data)
    height = -1
    width = -1
    content_type = ''
    # handle GIFs
    if (size >= 10) and data[:6] in ('GIF87a', 'GIF89a'):
        # Check to see if content_type is correct
        content_type = 'image/gif'
        w, h = struct.unpack("<HH", data[6:10])
        width = int(w)
        height = int(h)
    # See PNG 2. Edition spec (http://www.w3.org/TR/PNG/)
    # Bytes 0-7 are below, 4-byte chunk length, then 'IHDR'
    # and finally the 4-byte width, height
    elif ((size >= 24) and data.startswith('\211PNG\r\n\032\n') and (data[12:16] == 'IHDR')):
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[16:24])
        width = int(w)
        height = int(h)
    # Maybe this is for an older PNG version.
    elif (size >= 16) and data.startswith('\211PNG\r\n\032\n'):
        # Check to see if we have the right content type
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[8:16])
        width = int(w)
        height = int(h)
    # handle JPEGs
    elif (size >= 2) and data.startswith('\377\330'):
        content_type = 'image/jpeg'
        jpeg = StringIO.StringIO(data)
        jpeg.read(2)
        b = jpeg.read(1)
        try:
            while (b and ord(b) != 0xDA):
                while (ord(b) != 0xFF):
                    b = jpeg.read(1)
                while (ord(b) == 0xFF):
                    b = jpeg.read(1)
                if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
                    jpeg.read(3)
                    h, w = struct.unpack(">HH", jpeg.read(4))
                    break
                else:
                    jpeg.read(int(struct.unpack(">H", jpeg.read(2))[0]) - 2)
                b = jpeg.read(1)
            width = int(w)
            height = int(h)
        except struct.error:
            pass
        except ValueError:
            pass
    return content_type, width, height


def set_gps_location(md, lat, lng):
    """Adds GPS position as EXIF metadata
    file_name -- image file
    lat -- latitude (as float)
    lng -- longitude (as float)
    """
    lat_deg = to_deg(lat, ["S", "N"])
    lng_deg = to_deg(lng, ["W", "E"])
    # convert decimal coordinates into degrees, munutes and seconds
    exiv_lat = (pe.Rational(lat_deg[0] * 60 + lat_deg[1], 60), pe.Rational(lat_deg[2] * 100, 6000), pe.Rational(0, 1))
    exiv_lng = (pe.Rational(lng_deg[0] * 60 + lng_deg[1], 60), pe.Rational(lng_deg[2] * 100, 6000), pe.Rational(0, 1))
    # set the fields and return the metadata object
    md["Exif.GPSInfo.GPSLatitude"] = exiv_lat
    md["Exif.GPSInfo.GPSLatitudeRef"] = lat_deg[3]
    md["Exif.GPSInfo.GPSLongitude"] = exiv_lng
    md["Exif.GPSInfo.GPSLongitudeRef"] = lng_deg[3]
    md["Exif.Image.GPSTag"] = 654
    md["Exif.GPSInfo.GPSMapDatum"] = "WGS-84"
    md["Exif.GPSInfo.GPSVersionID"] = '2 0 0 0'
    return md


def main(args):
    """Main login function for the script
    """
    mdSrc = pe.ImageMetadata(args.infile.name)
    mdSrc.read()
    if not isinstance(args.dst_files, list):
        args.dst_files = [args.dst_files]

    if args.dst_files[0] is None:
        show_meta(mdSrc)
        print('No changes made')
        return

    # iterate over all files
    for f in args.dst_files:
        # get the metadata for destination image
        mdDst = pe.ImageMetadata(f.name)
        mdDst.read()
        # copy over the metadata from the source to the destination files
        for k in mdSrc.exif_keys:
            try:
                if re.compile('gps', re.I).search(k):
                    mdDst[k] = pe.ExifTag(k, mdSrc[k].value)
            except pe.exif.ExifValueError:
                pass
        for k in mdSrc.xmp_keys:
            try:
                mdDst[k] = pe.XmpTag(k, mdSrc[k].value)
            except:
                pass
        # now, overwrite the required xmp metadata values
        mdDst['Xmp.GPano:UsePanoramaViewer'] = pe.XmpTag('Xmp.GPano.UsePanoramaViewer', 'True')
        mdDst['Xmp.GPano.SourcePhotosCount'] = pe.XmpTag('Xmp.GPano.SourcePhotosCount', str(4))
        mdDst['Xmp.GPano.PoseHeadingDegrees'] = pe.XmpTag('Xmp.GPano.PoseHeadingDegrees', str(350.0))
        mdDst['Xmp.GPano.InitialViewHeadingDegrees'] = pe.XmpTag('Xmp.GPano.InitialViewHeadingDegrees', str(90.0))
        mdDst['Xmp.GPano.InitialViewPitchDegrees'] = pe.XmpTag('Xmp.GPano.InitialViewPitchDegrees', str(0.0))
        mdDst['Xmp.GPano.InitialViewRollDegrees'] = pe.XmpTag('Xmp.GPano.InitialViewRollDegrees', str(0.0))
        mdDst['Xmp.GPano.InitialHorizontalFOVDegrees'] = pe.XmpTag('Xmp.GPano.InitialHorizontalFOVDegrees', str(80.0))
        # set the CroppedAreaImageWidthPixels & CroppedAreaImageHeightPixels to the actual image size
        with open(f.name, 'r') as fdata:
            imageData = fdata.read()
        (imgType, imgW, imgH) = get_image_info(imageData)

        mdDst['Xmp.GPano.CroppedAreaImageWidthPixels'] = pe.XmpTag('Xmp.GPano.CroppedAreaImageWidthPixels', str(imgW))
        mdDst['Xmp.GPano.CroppedAreaImageHeightPixels'] = pe.XmpTag('Xmp.GPano.CroppedAreaImageHeightPixels', str(imgH))
        mdDst['Xmp.GPano.FullPanoWidthPixels'] = pe.XmpTag('Xmp.GPano.FullPanoWidthPixels', str(imgW))
        mdDst['Xmp.GPano.FullPanoHeightPixels'] = pe.XmpTag('Xmp.GPano.FullPanoHeightPixels', str(imgH))
        # and set these to zero
        mdDst['Xmp.GPano.CroppedAreaLeftPixels'] = pe.XmpTag('Xmp.GPano.CroppedAreaLeftPixels', str(0))
        mdDst['Xmp.GPano.CroppedAreaTopPixels'] = pe.XmpTag('Xmp.GPano.CroppedAreaTopPixels', str(0))
        # set exposure lock to true
        mdDst['Xmp.GPano.ExposureLockUsed'] = pe.XmpTag('Xmp.GPano.ExposureLockUsed', 'True')

        if args.gps:
            set_gps_location(mdDst, args.gps[0], args.gps[1])

        show_meta(mdDst)
        if query_yes_no('Would you like to write the above metadata to {}?'.format(f.name), default='no'):
            # write the metadata to the image
            mdDst.write()


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Set image metadata.')
    parser.add_argument('infile', type=argparse.FileType('r'), help='the image to set the metadata from')
    parser.add_argument('-d', '--destination', dest='dst_files', type=argparse.FileType('rw'), help='the file that will be overwritten with the given file\'s metadata')
    parser.add_argument('-g', '--gps', dest='gps', type=float, nargs=2, help='the longitude and latitude coordinates to set for the output image')
    args = parser.parse_args()
    main(args)