Doug Kerr
Well-known member
As many of you know, we are looking into the possibility of adopting Photoshop CS5 as our "workhorse" image editor. This has caused me to look into a number of its features that correspond to our very basic, "bread-and-butter" needs (cropping, basic masking, tonal curve adjustment, sharpening, resampling, etc.). I will discuss my observations in that regard elsewhere.
A collateral area in the overall workflow is the handling of metadata. I thought I would take a quick look into just what PS CS5 does in that area. Others here may have far greater insights into this than I, and I would enjoy any further observations, including corrections where I may have come to the wrong conclusions based on my limited tests.
By way of reference, all camera files spoken of here were JPEG files generated by a Canon EOS 40D. These contained:
• "Camera" Exif metadata
• Some "identification" Exif metadata
• Maker note Exif metadata
They contained no IPTC metadata (in either IIM or XMP forms).
Metadata in the various files involved was inspected with three tools:
• Opanda IExif (which can be used to inspect metadata in files downloaded from Web pages
• ExifTool/ExifToolGUI
• GexifView
Basic scenario
The basic number I asked PS CS5 to do at its recital was to open a camera file and then do a Save As.
The result seems to be this:
• "Camera" Exif metadata (describing the camera and the circumstances of the exposure) is written to the destination file.
• "Maker Note" Exif metadata is not in general written to the destination file.
• Some "Identification" Exif metadata is constructed and written to the destination file. Notably, the OwnerName is extracted from the Maker Note metadata and applied as the Artist data item. The role of Photoshop in the process is also recorded in that area.
• Certain IPTC metadata in XMP form is created and written, including both OwnerName and Creator items, both drawn from the OwnerName item in the Maker Note Exif metadata.
• Certain IPTC metadata in IIM (legacy) form is created and written. The main item here is Byline, taken from the OwnerName item in the Maker Note Exif metadata.
Original file includes IPTC metadata
It appears that if the incoming file included IPTC metadata, that is preserved and written to the destination file. There are some details of this I have not yet checked out.
Addition of further IPTC metadata
The user can enter a wide range of IPTC metadata items in the File Info dialog. There are not separate screens for IIM and XMP IPTC data. Entries made will turn into data items in one or both forms, as appropriate (not always with identical tag names).
There is a separate screen for IPTC extension metadata. This is a new aspect of the IPTC format providing further information of interest to photographers and publishers. It actually goes into the XMP form of the IPTC metadata area.
Metadata templates
A use can save all the metadata in force for the currently-open image to a metadata template. (The metadata cannot be screened; that is, we cannot elect to have IPTC metadata but not camera metadata, if present, saved to the template.
With an image loaded, a saved metadata template can be summoned, in one of three modes of effect:
• Clear all existing metadata items and place whatever metadata is in the template.
• Update all items for which there are values in the template and keep all other items unchanged.
• Append the values in the template to the existing values for the corresponding items (for text values; we cannot append a new shutter speed to the existing one).
I had somehow expected to find a provisions for automatically adding, by default, certain user-determined metadata items (perhaps a fully-worded copyright notice, or "standard" usage limitations) to each file when it is saved by Photoshop, but with the few exceptions noted above (based on the OwnerName in the Maker Note Exif metadata), I find no such provisions. Perhaps a colleague knows how this works.
Well, that's what we know here, so far.
A collateral area in the overall workflow is the handling of metadata. I thought I would take a quick look into just what PS CS5 does in that area. Others here may have far greater insights into this than I, and I would enjoy any further observations, including corrections where I may have come to the wrong conclusions based on my limited tests.
By way of reference, all camera files spoken of here were JPEG files generated by a Canon EOS 40D. These contained:
• "Camera" Exif metadata
• Some "identification" Exif metadata
• Maker note Exif metadata
They contained no IPTC metadata (in either IIM or XMP forms).
Metadata in the various files involved was inspected with three tools:
• Opanda IExif (which can be used to inspect metadata in files downloaded from Web pages
• ExifTool/ExifToolGUI
• GexifView
Basic scenario
The basic number I asked PS CS5 to do at its recital was to open a camera file and then do a Save As.
The result seems to be this:
• "Camera" Exif metadata (describing the camera and the circumstances of the exposure) is written to the destination file.
• "Maker Note" Exif metadata is not in general written to the destination file.
This is metadata in proprietary format covering a wide range of items, including (for the Canon EOS cameras) the owner's name (if it had been embedded in the camera) and the details of color correction vectors.
• Some "Identification" Exif metadata is constructed and written to the destination file. Notably, the OwnerName is extracted from the Maker Note metadata and applied as the Artist data item. The role of Photoshop in the process is also recorded in that area.
• Certain IPTC metadata in XMP form is created and written, including both OwnerName and Creator items, both drawn from the OwnerName item in the Maker Note Exif metadata.
• Certain IPTC metadata in IIM (legacy) form is created and written. The main item here is Byline, taken from the OwnerName item in the Maker Note Exif metadata.
Original file includes IPTC metadata
It appears that if the incoming file included IPTC metadata, that is preserved and written to the destination file. There are some details of this I have not yet checked out.
Addition of further IPTC metadata
The user can enter a wide range of IPTC metadata items in the File Info dialog. There are not separate screens for IIM and XMP IPTC data. Entries made will turn into data items in one or both forms, as appropriate (not always with identical tag names).
There is a separate screen for IPTC extension metadata. This is a new aspect of the IPTC format providing further information of interest to photographers and publishers. It actually goes into the XMP form of the IPTC metadata area.
Metadata templates
A use can save all the metadata in force for the currently-open image to a metadata template. (The metadata cannot be screened; that is, we cannot elect to have IPTC metadata but not camera metadata, if present, saved to the template.
With an image loaded, a saved metadata template can be summoned, in one of three modes of effect:
• Clear all existing metadata items and place whatever metadata is in the template.
• Update all items for which there are values in the template and keep all other items unchanged.
• Append the values in the template to the existing values for the corresponding items (for text values; we cannot append a new shutter speed to the existing one).
I had somehow expected to find a provisions for automatically adding, by default, certain user-determined metadata items (perhaps a fully-worded copyright notice, or "standard" usage limitations) to each file when it is saved by Photoshop, but with the few exceptions noted above (based on the OwnerName in the Maker Note Exif metadata), I find no such provisions. Perhaps a colleague knows how this works.
Well, that's what we know here, so far.
Last edited: