SUGGESTION: URI in the meta data of SVG.PNG files

[saxtron3000]

This way, users can redraw/modify their character from a downloaded image.

• Write SVG data
• Read SVG data
• Write PNG data
• Read PNG data

[millette]

SVG already supports this (URL written to Copyright meta data).

For png, see https://sharp.pixelplumbing.com/api-output#withmetadata

https://exiftool.org https://www.npmjs.com/package/exiftool-vendored

Notes from https://exiftool.org/TagNames/EXIF.html:

ImageUniqueID string ExifIFD
ImageDescription string IFD0

For png, also add Copyright info:

Copyright string IFD0 (may contain copyright notices for photographer and editor, separated by a newline. As per the EXIF specification, the newline is replaced by a null byte when writing to file, but this may be avoided by disabling the print conversion)

This would take care of writing the data. Reading and interpreting would be the next task.

[millette]

After a few tries it looks like sharp doesn't support png metadata. We have the option to save jpeg instead of png (smaller file - although compressed, the svg is always available for pristine quality) or turn to an external tool to save png metadata.

• https://exiftool.org/
• https://www.npmjs.com/package/exiftool-vendored

[millette]

const ExifTool = require("exiftool-vendored").ExifTool
const exiftool = new ExifTool({ taskTimeoutMillis: 500 })

async function runner() {
  await exiftool
    .write("oyoy-6.png", {
      "PNG:SOURCE": "https://charactercreator.org/#skinColor=%235c3836&irisColor=%23552200&hairColor=%231a1a1a&pupils=round&sex=m&body_head=oblong&ears=outstretched&nose=syrid&emotion=omg&shirt=turtleneck&shirtColor=%23BEE9C5&pants=cargo&pantsColor=%23b19f92&belt=utility&hat=chinese_farmer&hatColor=%23b19f92&glasses=round&shoes=loafers&tie=neck&tieColor=%23b19f92"
    })
  exiftool.end()
}

runner().catch(console.error)

Et on trouve le output:

{
  SourceFile: '/home/millette/exif/oyoy-6.png',
  errors: [],
  ExifToolVersion: 12.4,
  FileName: 'oyoy-6.png',
  Directory: '/home/millette/exif',
  FileSize: '111 KiB',
  FileModifyDate: ExifDateTime {
    year: 2022,
    month: 4,
    day: 9,
    hour: 14,
    minute: 48,
    second: 55,
    millisecond: 0,
    tzoffsetMinutes: -240,
    rawValue: '2022:04:09 14:48:55-04:00',
    zoneName: 'UTC-4'
  },
  FileAccessDate: ExifDateTime {
    year: 2022,
    month: 4,
    day: 9,
    hour: 14,
    minute: 48,
    second: 55,
    millisecond: 0,
    tzoffsetMinutes: -240,
    rawValue: '2022:04:09 14:48:55-04:00',
    zoneName: 'UTC-4'
  },
  FileInodeChangeDate: ExifDateTime {
    year: 2022,
    month: 4,
    day: 9,
    hour: 14,
    minute: 48,
    second: 55,
    millisecond: 0,
    tzoffsetMinutes: -240,
    rawValue: '2022:04:09 14:48:55-04:00',
    zoneName: 'UTC-4'
  },
  FilePermissions: '-rw-rw-r--',
  FileType: 'PNG',
  FileTypeExtension: 'png',
  MIMEType: 'image/png',
  ImageWidth: 1000,
  ImageHeight: 1000,
  BitDepth: 8,
  ColorType: 'RGB with Alpha',
  Compression: 'Deflate/Inflate',
  Filter: 'Adaptive',
  Interlace: 'Noninterlaced',
  PixelsPerUnitX: 2835,
  PixelsPerUnitY: 2835,
  PixelUnits: 'meters',
  Source: 'https://charactercreator.org/#skinColor=%235c3836&irisColor=%23552200&hairColor=%231a1a1a&pupils=round&sex=m&body_head=oblong&ears=outstretched&nose=syrid&emotion=omg&shirt=turtleneck&shirtColor=%23BEE9C5&pants=cargo&pantsColor=%23b19f92&belt=utility&hat=chinese_farmer&hatColor=%23b19f92&glasses=round&shoes=loafers&tie=neck&tieColor=%23b19f92',
  CodedCharacterSet: 'UTF8',
  EnvelopeRecordVersion: 4,
  ImageSize: '1000x1000',
  Megapixels: 1
}

Voici l'exemple png:

[millette]

One more thing: webp format (supports non-lossy compression, à la png) works with sharp and it also supports exif metadata. It's probably the best option, if we wish to change image format.

[saxtron3000]

What do you think Fred? Best to stick with PNG and SVG? Pablo Saxtron, Operations The Character Creator https://charactercreator.org/

…

On Sat, Apr 9, 2022 at 3:27 PM Robin Millette ***@***.***> wrote: One more thing: *webp* format (supports non-lossy compression, à la png) works with sharp and it also supports exif metadata. It's probably the best option, if we wish to change image format. — Reply to this email directly, view it on GitHub <#212 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ATC4DBPZZZZMTCMKHHZDKE3VEHK3NANCNFSM5S5FYFVA> . You are receiving this because you authored the thread.Message ID: ***@***.***>