Unable to read Nikon EXIF tags

Question

Unable to read Nikon EXIF tags

Richard Rosenheim 86

I've encountered a problem reading certain EXIF tags from Nikon cameras. I've tested images taken with couple different Canon cameras (no problems) and several Nikon cameras (D850, D5, D6, Z9). With the images from the various Nikon cameras, .NET (I'm using .NET Framework 4.8), is not returning the values for both the Artists (ie., Authors) (EXIF tag 0x013B) and the Copyright (EXIF tag 0x8298) tags.

I've tried using both the GetPropertyItem and the PropertyItems methods of an image of System.Drawing.Image type.

With GetPropertyItem, I get 'System.ArgumentException' being thrown by the System.Drawing.dll when I attempt to retrieve those fields, which is expected behavior when trying to retrieve an EXIF tag that doesn't exists.

With PropertyItems, those tags are not returned. And I've looked through the tags that PropertyItems do return to see if the information might be getting returned as a different tag. No such luck.

The information is being stored in the images. I've confirmed that both by looking at the hex dump of the image file, and also when I right-click on the image in Windows Explorer and do Properties, Details, the information is shown in the dialog box.

Does anyone have any ideas/solutions of how I can retrieve the information?

TIA,

Richard

Viorel 122.6K Reputation points

2023-03-04T06:45:02.17+00:00

Maybe you should attach a sample problematic image. There is an alternative C++ code that can be tried: https://learn.microsoft.com/en-us/windows/win32/gdiplus/-gdiplus-reading-and-writing-metadata-use.

Did you try the .NET 7?
Richard Rosenheim 86 Reputation points

2023-03-06T07:15:20.2433333+00:00

Viorel,

Thanks for replying. As you suggested, I tried using .NET 7. Same issue.

The link you provided, plus some Google searching, led me to this link:

https://stackoverflow.com/questions/2280948/reading-data-metadata-from-jpeg-xmp-or-exif-in-c-sharp

and the reply/code posted by Mitselplik.

I also gave ImageSharp a try. Both Mitselplik's solution and ImageSharp works, they are able to retrieve the problematic tags. But they both requires that the image is accessed from disk.

The issue with both of those 'solutions' is that I am already incurring the overhead of loading the image into memory for other processing. Based upon some quick bench marking, having to access/load the image a second time is adding over 1/3 second per image using the Shell32 approach, and over 1/2 second per image using ImageSharp. When processing many thousands of images, that does have a noticeable culminated impact.

It would be nicer if I could find a solution that would work with the System.Drawing.Image object that I already have instantiated.

As requested, I tried to attach a sample photograph that illustrates the issue when using GetPropertyItem or PropertyItems. But, when I tried reducing the size of the photograph so I could attach it (there's a 3MB limit on attachments), the programs are fixing the issue when they save the reduced image back to disk. I tried both Photoshop and Paint.
Jack J Jun 25,296 Reputation points

2023-03-06T07:18:35.1166667+00:00

@Richard Rosenheim, Welcome to Microsoft Q&A, if you have trouble in uploading the picture here, I recommend that you could upload pictures via GitHub.

With GetPropertyItem, I get 'System.ArgumentException' being thrown by the System.Drawing.dll when I attempt to retrieve those fields, which is expected behavior when trying to retrieve an EXIF tag that doesn't exists. With PropertyItems, those tags are not returned. And I've looked through the tags that PropertyItems do return to see if the information might be getting returned as a different tag. No such luck.

Could you provide some code with me?

Richard Rosenheim 86

Here's some sample code that I've simplified down to the bare essential.

    Const EXIF_ArtistName As UInt16 = &H13B

    Dim img As Bitmap
    Dim prop As System.Drawing.Imaging.PropertyItem
    Dim value As String

    img = New Bitmap(fileName)
    prop = img.GetPropertyItem(EXIF_ArtistName)
    value = System.Text.Encoding.UTF7.GetString(prop.Value, 0, prop.Len - 1)  ' remove trailing 00H character

If the image being loaded is from a Canon camera, it's works. With Nikon cameras, the GetPropertyItem call will generate an exception.

Jack J Jun 25,296 Reputation points

2023-03-14T06:54:24.71+00:00

@Richard Rosenheim, thanks for providing code, as you mentioned, the GetPropertyItem call will generate an exception when you used Nikon cameras. could you provide a picture so that I could make a test for it?
Richard Rosenheim 86 Reputation points

2023-03-15T05:21:30.59+00:00

As I mentioned before, this forum won't allow me to upload file that big. So, I've placed a sample photo on a cloud storage. Here's the shared linked:

https://app.box.com/s/wwltqsks3r24i8ugxb4ztmyh97hd22wn
Jiachen Li-MSFT 34,221 Reputation points Microsoft External Staff

2023-03-15T07:50:36.07+00:00

Hi @Richard Rosenheim ,
When I try to modify the author from the File property, the photo PropertyItems contains the Artist property and it can be read.

So this may be a bug specific to photos exported from a Nikon camera.

It is recommended that you post the problem on https://github.com/dotnet/runtime/issues.

Your answer

Viorel 122.6K Reputation points

2023-03-04T06:45:02.17+00:00

Maybe you should attach a sample problematic image. There is an alternative C++ code that can be tried: https://learn.microsoft.com/en-us/windows/win32/gdiplus/-gdiplus-reading-and-writing-metadata-use.

Did you try the .NET 7?
Richard Rosenheim 86 Reputation points

2023-03-06T07:15:20.2433333+00:00

Viorel,

Thanks for replying. As you suggested, I tried using .NET 7. Same issue.

The link you provided, plus some Google searching, led me to this link:

https://stackoverflow.com/questions/2280948/reading-data-metadata-from-jpeg-xmp-or-exif-in-c-sharp

and the reply/code posted by Mitselplik.

I also gave ImageSharp a try. Both Mitselplik's solution and ImageSharp works, they are able to retrieve the problematic tags. But they both requires that the image is accessed from disk.

The issue with both of those 'solutions' is that I am already incurring the overhead of loading the image into memory for other processing. Based upon some quick bench marking, having to access/load the image a second time is adding over 1/3 second per image using the Shell32 approach, and over 1/2 second per image using ImageSharp. When processing many thousands of images, that does have a noticeable culminated impact.

It would be nicer if I could find a solution that would work with the System.Drawing.Image object that I already have instantiated.

As requested, I tried to attach a sample photograph that illustrates the issue when using GetPropertyItem or PropertyItems. But, when I tried reducing the size of the photograph so I could attach it (there's a 3MB limit on attachments), the programs are fixing the issue when they save the reduced image back to disk. I tried both Photoshop and Paint.
Jack J Jun 25,296 Reputation points

2023-03-06T07:18:35.1166667+00:00

@Richard Rosenheim, Welcome to Microsoft Q&A, if you have trouble in uploading the picture here, I recommend that you could upload pictures via GitHub.

With GetPropertyItem, I get 'System.ArgumentException' being thrown by the System.Drawing.dll when I attempt to retrieve those fields, which is expected behavior when trying to retrieve an EXIF tag that doesn't exists. With PropertyItems, those tags are not returned. And I've looked through the tags that PropertyItems do return to see if the information might be getting returned as a different tag. No such luck.

Could you provide some code with me?
Richard Rosenheim 86 Reputation points

2023-03-13T08:58:07.11+00:00

Here's some sample code that I've simplified down to the bare essential.

Const EXIF_ArtistName As UInt16 = &H13B Dim img As Bitmap Dim prop As System.Drawing.Imaging.PropertyItem Dim value As String img = New Bitmap(fileName) prop = img.GetPropertyItem(EXIF_ArtistName) value = System.Text.Encoding.UTF7.GetString(prop.Value, 0, prop.Len - 1) ' remove trailing 00H character

If the image being loaded is from a Canon camera, it's works. With Nikon cameras, the GetPropertyItem call will generate an exception.
Jack J Jun 25,296 Reputation points

2023-03-14T06:54:24.71+00:00

@Richard Rosenheim, thanks for providing code, as you mentioned, the GetPropertyItem call will generate an exception when you used Nikon cameras. could you provide a picture so that I could make a test for it?
Richard Rosenheim 86 Reputation points

2023-03-15T05:21:30.59+00:00

As I mentioned before, this forum won't allow me to upload file that big. So, I've placed a sample photo on a cloud storage. Here's the shared linked:

https://app.box.com/s/wwltqsks3r24i8ugxb4ztmyh97hd22wn
Jiachen Li-MSFT 34,221 Reputation points Microsoft External Staff

2023-03-15T07:50:36.07+00:00

Hi @Richard Rosenheim ,
When I try to modify the author from the File property, the photo PropertyItems contains the Artist property and it can be read.

So this may be a bug specific to photos exported from a Nikon camera.

It is recommended that you post the problem on https://github.com/dotnet/runtime/issues.

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Unable to read Nikon EXIF tags

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