Include Fileset Alt Text Field Values In IIIF Manifest For Works

[KevinJonesMeta]

Descriptive summary

Alt text will be embedded in files (primarily image files) and extracted to the fileset for display in Oregon Digital (see related ticket). The alt text metadata extracted to the fileset needs to be included in the IIIF manifest so that the data can travel with the work in an analogous manner to it travelling with the file when the file is downloaded.

Expected behavior

Related work

(#3637)

Accessibility Concerns

The distribution of alt text metadata with the IIIF manifest supports WCAG 2.1 compliance.

[CGillen]

All the metadata extracted by the exiftool utility used in FITS:

$ perl /opt/fits/tools/exiftool/perl/exiftool ./p120_3375_bd.tif 
ExifTool Version Number         : 12.50
File Name                       : p120_3375_bd.tif
Directory                       : .
File Size                       : 111 MB
File Modification Date/Time     : 2026:05:26 22:30:59+00:00
File Access Date/Time           : 2026:05:26 22:31:14+00:00
File Inode Change Date/Time     : 2026:05:26 22:31:12+00:00
File Permissions                : -rw-r--r--
File Type                       : TIFF
File Type Extension             : tif
MIME Type                       : image/tiff
Exif Byte Order                 : Big-endian (Motorola, MM)
Subfile Type                    : Full-resolution image
Image Width                     : 7407
Image Height                    : 4978
Bits Per Sample                 : 8 8 8
Compression                     : Uncompressed
Photometric Interpretation      : RGB
Image Description               : A. S. Miller unloading metal sided wheel barrow filled with chicken feed inside chicken house. Many chickens are standing near wheel barrow.
Strip Offsets                   : 28230
Orientation                     : Horizontal (normal)
Samples Per Pixel               : 3
Rows Per Strip                  : 4978
Strip Byte Counts               : 110616138
X Resolution                    : 800
Y Resolution                    : 800
Planar Configuration            : Chunky
Resolution Unit                 : inches
Software                        : Adobe Photoshop 26.0 (Macintosh)
Modify Date                     : 2026:05:14 08:02:57
XMP Toolkit                     : Adobe XMP Core 9.1-c002 79.b7c64ccf9, 2024/07/16-12:39:04
Format                          : image/tiff
Source                          : photographs
Contributor                     : Oregon State University Libraries and Press, Special Collections and Archives Research Center, Digital Production Unit, Crystal Lohne, Brian E. Davis
Type                            : Image
Description                     : A. S. Miller unloading metal sided wheel barrow filled with chicken feed inside chicken house. Many chickens are standing near wheel barrow.
Description (x-repair)          : A. S. Miller unloading metal sided wheel barrow filled with chicken feed inside chicken house. Many chickens are standing near wheel barrow.
Creator Tool                    : Adobe Photoshop 26.0 (Macintosh)
Metadata Date                   : 2026:05:14 08:02:57-07:00
Document ID                     : xmp.did:09f8c1eb-8c31-4566-b7c2-8757cdad7e76
Instance ID                     : xmp.iid:92133d13-5b8d-42ec-926a-8414e2d6b8d2
Original Document ID            : xmp.did:09f8c1eb-8c31-4566-b7c2-8757cdad7e76
History Action                  : created, saved, saved, saved, saved, saved, saved, saved
History Instance ID             : xmp.iid:09f8c1eb-8c31-4566-b7c2-8757cdad7e76, xmp.iid:17bd9dcf-e492-44fa-8b89-fc93515df92a, xmp.iid:373f3631-78b8-4815-87cd-e55ec8bf6002, xmp.iid:e456e025-4caa-464c-842c-a1cb47eaea6f, xmp.iid:d74d6ddc-5b66-440b-8518-571564b6a8e1, xmp.iid:b4430a93-8365-42f8-adb0-619d455cc295, xmp.iid:801510f3-3b4c-49fe-9832-b3c38a5a2a48, xmp.iid:92133d13-5b8d-42ec-926a-8414e2d6b8d2
History Software Agent          : Adobe Photoshop 26.0 (Macintosh), Adobe Photoshop Camera Raw 17.0, Adobe Photoshop Camera Raw 17.0 (Macintosh), Adobe Photoshop 26.0 (Macintosh), Adobe Photoshop 26.0 (Macintosh), Adobe Photoshop Camera Raw 17.0, Adobe Photoshop Camera Raw 17.0 (Macintosh), Adobe Photoshop 26.0 (Macintosh)
History When                    : 2025:07:02 14:37:55-07:00, 2025:07:21 11:10:23-07:00, 2025:07:21 11:10:23-07:00, 2025:10:30 10:12:50-07:00, 2025:10:30 10:15:51-07:00, 2026:05:14 07:51:14-07:00, 2026:05:14 07:51:14-07:00, 2026:05:14 08:02:57-07:00
History Changed                 : /metadata, /metadata, /, /, /metadata, /metadata, /
Legacy IPTC Digest              : 09283F5A1247F295DE56B756F9A50933
Color Mode                      : RGB
ICC Profile Name                : Adobe RGB (1998)
History                         : 2026-05-14T08:02:01-07:00.File p120_3375_bd.tif opened.Open.false.true./Users/tvc15/Desktop/p120_3375_bd.tif.68.false..Crop.Crop.Crop.Image Size.Image Size.Resolution: 300 per inch.With Scale Styles.With Constrain Proportions.Interpolation: automatic..2026-05-14T08:02:17-07:00.File p120_3375_bd.tif saved.Save..2026-05-14T08:02:57-07:00.File p120_3375_bd.tif saved.
Alt Text Accessibility          : A. S. Miller unloading metal sided wheel barrow filled with chicken feed inside chicken house. Many chickens are standing near wheel barrow.
Current IPTC Digest             : e1555159a43634adc25aaf9fa1567684
Coded Character Set             : UTF8
Application Record Version      : 4
Caption-Abstract                : A. S. Miller unloading metal sided wheel barrow filled with chicken feed inside chicken house. Many chickens are standing near wheel barrow.
Digital Creation Date           : 2025:07:02
IPTC Digest                     : e1555159a43634adc25aaf9fa1567684
Displayed Units X               : inches
Displayed Units Y               : inches
Print Style                     : Centered
Print Position                  : 0 0
Print Scale                     : 1
Global Angle                    : 30
Global Altitude                 : 30
URL List                        : 
Slices Group Name               : p120_3375_bd
Num Slices                      : 1
Pixel Aspect Ratio              : 1
Photoshop Thumbnail             : (Binary data 4415 bytes, use -b option to extract)
Has Real Merged Data            : Yes
Writer Name                     : Adobe Photoshop
Reader Name                     : Adobe Photoshop 2025
Exif Version                    : 0231
Create Date                     : 2025:07:02 14:37:55
Offset Time                     : -07:00
Color Space                     : Uncalibrated
Exif Image Width                : 7407
Exif Image Height               : 4978
Profile CMM Type                : Adobe Systems Inc.
Profile Version                 : 2.1.0
Profile Class                   : Display Device Profile
Color Space Data                : RGB
Profile Connection Space        : XYZ
Profile Date Time               : 1999:06:03 00:00:00
Profile File Signature          : acsp
Primary Platform                : Apple Computer Inc.
CMM Flags                       : Not Embedded, Independent
Device Manufacturer             : none
Device Model                    : 
Device Attributes               : Reflective, Glossy, Positive, Color
Rendering Intent                : Media-Relative Colorimetric
Connection Space Illuminant     : 0.9642 1 0.82491
Profile Creator                 : Adobe Systems Inc.
Profile ID                      : 0
Profile Copyright               : Copyright 1999 Adobe Systems Incorporated
Profile Description             : Adobe RGB (1998)
Media White Point               : 0.95045 1 1.08905
Media Black Point               : 0 0 0
Red Tone Reproduction Curve     : (Binary data 14 bytes, use -b option to extract)
Green Tone Reproduction Curve   : (Binary data 14 bytes, use -b option to extract)
Blue Tone Reproduction Curve    : (Binary data 14 bytes, use -b option to extract)
Red Matrix Column               : 0.60974 0.31111 0.01947
Green Matrix Column             : 0.20528 0.62567 0.06087
Blue Matrix Column              : 0.14919 0.06322 0.74457
Image Size                      : 7407x4978
Megapixels                      : 36.9
Modify Date                     : 2026:05:14 08:02:57-07:00

It seems to capture the data, assuming Alt Text Accessibility is the correct field.

Now the tricky part, FITS doesn't see that field:

$ /opt/fits/fits.sh -i ./p120_3375_bd.tif
<?xml version="1.0" encoding="UTF-8"?>
<fits xmlns="http://hul.harvard.edu/ois/xml/ns/fits/fits_output" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://hul.harvard.edu/ois/xml/ns/fits/fits_output http://hul.harvard.edu/ois/xml/xsd/fits/fits_output.xsd" version="1.6.0" timestamp="5/26/26, 10:44 PM">
  <identification>
    <identity format="TIFF EXIF" mimetype="image/tiff" toolname="FITS" toolversion="1.6.0">
      <tool toolname="Jhove" toolversion="1.26.1" />
      <tool toolname="Exiftool" toolversion="12.50" />
      <version toolname="Jhove" toolversion="1.26.1">6.0</version>
    </identity>
  </identification>
  <fileinfo>
    <size toolname="Jhove" toolversion="1.26.1">110644476</size>
    <creatingApplicationName toolname="Exiftool" toolversion="12.50" status="SINGLE_RESULT">Adobe Photoshop 26.0 (Macintosh)</creatingApplicationName>
    <lastmodified toolname="Exiftool" toolversion="12.50">2026-05-14T08:02:57</lastmodified>
    <created toolname="Exiftool" toolversion="12.50" status="CONFLICT">2025-07-02T14:37:55</created>
    <created toolname="Tika" toolversion="2.6.0" status="CONFLICT">2026-05-14T08:02:57</created>
    <filepath toolname="OIS File Information" toolversion="1.0" status="SINGLE_RESULT">/data/./p120_3375_bd.tif</filepath>
    <filename toolname="OIS File Information" toolversion="1.0" status="SINGLE_RESULT">p120_3375_bd.tif</filename>
    <md5checksum toolname="OIS File Information" toolversion="1.0" status="SINGLE_RESULT">9a315dde0825794fd015a1c5ed9802d9</md5checksum>
    <fslastmodified toolname="OIS File Information" toolversion="1.0" status="SINGLE_RESULT">1779834659452</fslastmodified>
  </fileinfo>
  <filestatus>
    <well-formed toolname="Jhove" toolversion="1.26.1" status="SINGLE_RESULT">true</well-formed>
    <valid toolname="Jhove" toolversion="1.26.1" status="SINGLE_RESULT">true</valid>
  </filestatus>
  <metadata>
    <image>
      <byteOrder toolname="Jhove" toolversion="1.26.1" status="SINGLE_RESULT">big endian</byteOrder>
      <compressionScheme toolname="Jhove" toolversion="1.26.1">Uncompressed</compressionScheme>
      <imageWidth toolname="Jhove" toolversion="1.26.1">7407</imageWidth>
      <imageHeight toolname="Jhove" toolversion="1.26.1">4978</imageHeight>
      <colorSpace toolname="Jhove" toolversion="1.26.1">RGB</colorSpace>
      <referenceBlackWhite toolname="Jhove" toolversion="1.26.1" status="SINGLE_RESULT">0 255 0 255 0 255</referenceBlackWhite>
      <iccProfileName toolname="Jhove" toolversion="1.26.1">Adobe RGB (1998)</iccProfileName>
      <orientation toolname="Jhove" toolversion="1.26.1">normal*</orientation>
      <samplingFrequencyUnit toolname="Jhove" toolversion="1.26.1">in.</samplingFrequencyUnit>
      <xSamplingFrequency toolname="Jhove" toolversion="1.26.1">800</xSamplingFrequency>
      <ySamplingFrequency toolname="Jhove" toolversion="1.26.1">800</ySamplingFrequency>
      <bitsPerSample toolname="Jhove" toolversion="1.26.1">8 8 8</bitsPerSample>
      <samplesPerPixel toolname="Jhove" toolversion="1.26.1">3</samplesPerPixel>
      <scanningSoftwareName toolname="Jhove" toolversion="1.26.1">Adobe Photoshop 26.0 (Macintosh)</scanningSoftwareName>
      <iccProfileVersion toolname="Exiftool" toolversion="12.50" status="SINGLE_RESULT">2.1.0</iccProfileVersion>
      <exifVersion toolname="Exiftool" toolversion="12.50" status="SINGLE_RESULT">0231</exifVersion>
    </image>
  </metadata>
  <statistics fitsExecutionTime="2216">
    <tool toolname="MediaInfo" toolversion="23.04" status="did not run" />
    <tool toolname="OIS Audio Information" toolversion="0.1" status="did not run" />
    <tool toolname="ADL Tool" toolversion="0.1" status="did not run" />
    <tool toolname="VTT Tool" toolversion="0.1" status="did not run" />
    <tool toolname="Droid" toolversion="6.5.2" executionTime="506" />
    <tool toolname="jpylyzer" toolversion="2.1.0" status="did not run" />
    <tool toolname="Jhove" toolversion="1.26.1" executionTime="406" />
    <tool toolname="embARC" toolversion="0.2" status="did not run" />
    <tool toolname="file utility" toolversion="5.44" executionTime="346" />
    <tool toolname="Exiftool" toolversion="12.50" executionTime="359" />
    <tool toolname="NLNZ Metadata Extractor" toolversion="3.6GA" status="did not run" />
    <tool toolname="OIS File Information" toolversion="1.0" executionTime="270" />
    <tool toolname="OIS XML Metadata" toolversion="0.2" status="did not run" />
    <tool toolname="ffident" toolversion="0.2" executionTime="304" />
    <tool toolname="Tika" toolversion="2.6.0" executionTime="2199" />
  </statistics>
</fits>

The information exists and FITS has the tools to find them but doesn't seem to be surfacing those findings. I'm going to guess FITS has some allowlist of metadata fields or something that it knows how to format.
This'll take some more research into FITS or the characterization process and see if they left any config or somewhere to hook in

[KevinJonesMeta]

@CGillen This is promising. Per #3637 , we are planning to populate both Alt Text Accessibility and Image Description with the same value because a lot of standard image viewers don't display or seem to recognize Alt Text Accessibility (aka, IPTC Alt Text), and we want it to be easy to find and not dependent on Photoshop or ExifTool (which I just met and like a lot).

[CGillen]

On whether IIIF can support metadata for filesets:
There are 2-ish options that I've seen.

(hard, new code, no hook) https://iiif.io/api/presentation/3.0/#metadata IIIF supports metadata on individual canvases (a rough equivalent to a file in a fileset or a page in a pdf) as a SHOULD be rendered. It also supports it on all items, so we may be able to find a better IIIF object that maps to filesets, but that is only a MAY render so it probably won't be visible in UV that way.

(easy, existing hook) The other option I saw is that we do have a hook into the metadata that displays on the main IIIF document (rough equivalent of the work), and we can label them arbitrarily, so we could add <fs_pid> alt text: <alt_text> or something

[lamtu1]

@KevinJonesMeta I am currently doing implementation following Corey's advice from the second option and implemented on the work-level manifest. Below is the screenshot of the manifest and was wondering if this is good to you or need to refine more detail?

[KevinJonesMeta]

@lamtu1 I don't do anything with the manifest so I've relied on what developers have said about it. You and Corey know more than me so I'm pretty much relying on your judgement. @carakey, do you know more about the manifest such you can comment about this?

[lamtu1]

I can always do a reach out and see what they say about the IIIF and go from there. Thank you for letting me know though.

[carakey]

@KevinJonesMeta

I haven't worked with the manifest either. I think I'm understanding this as, the manifest / slide-out metadata in the viewer (?) would display all the alt text values for all the work's filesets simultaneously, with the PID as the label for each - yes? So in the example, a user would get:

f0vq27zn406 - Alternative Text: a picture of a waterfall
f1vq27zn406 - Alternative Text: a picture of a pagoda

Having them all display simultaneously is fine, probably. I worry about using the fileset ID as the label value, not sure it has meaning for users, and seems pretty jarring if read by a screen reader (not sure if that's in the mix or not).