php's exif_read_data can't read GPS data on some images

[Phil Harvey]

Hi Geoff,

Did you start by copying the good version to "test.jpg"?

I suggest that you don't just follow my instructions blindly.  Instead, think about what you are doing and use your own detective skills along with exiftool to determine what the important differences are.

- Phil

[geoffschultz]

Yes, I did copy it & I have been experimenting with other options.  I stripped everything by doing an exiftool -all= test.jpg and I'm currently adding things back in.  I first added EXIF and while exiftool shows the GPS data, php can't read it.  I'm trying to figure out if I can delete sections of the EXIF data, but that's as far as I've gotten.

The unfortunate issue is that I know just enough to be dangerous...

-- Geoff

[geoffschultz]

Oh stupid me!  I've copied bad.jpg to test.jpg!

[geoffschultz]

The problem appears to be the makernotes.  As soon as I add them back in, php can no longer read the GPS metadata.  I can delete the makernotes and have it function properly.  This it appears that I have 1 or 2 options.

1) Write a script to delete the makernotes from any unedited image
2) To get exiftool to modify the makernotes into a format similar to what Photoshop is doing. 

Is #2 possible?  I'd prefer not to lose the makernotes, but I have copies of the unedited files elsewhere should I ever need that info.

-- Geoff

[Phil Harvey]

Hi Geoff,

Photoshop deletes the maker notes of edited images.

- Phil

[geoffschultz]

For anyone else who might be having similar issues, here's how I ended up solving it.

I decided to write a Power Shell script and found the following code to extract EXIF/IPTC/etc fields:

Code Select Expand


#Constants for Strings
$ExifIDDateTimeTaken           = 36867 #  0x9003
$ExifIDImageDescription        = 270   #  0x010E
$ExifIDMake                    = 271   #  0x010F
$ExifIDModel                   = 272   #  0x0110
$ExifIDSoftware                = 305   #  0x0131
$ExifIDArtist                  = 315   #  0x013B
$ExifIDCopyright               = 33432 #  0x8298
$ExifIDGPSLatRef               = 1
$ExifIDGPSLongRef              = 3
$ExifIDGPSAltRef               = 5

#Constants For Unicode strings
$ExifIDTitle                   = 40091 #  0x9C9B XP Title     binary data
$ExifIDAuthor                  = 40093 #  0x9C9D XP Author
$ExifIDKeywords                = 40094 #  0x9C9E XP Keywords
$ExifIDSubject                 = 40095 #  0x9C9F XP Subject

#$ExifIDComment                 = 40092 #  0x9C9C XP Comment
$ExifIDComment                 = 37510 #  0x9286 UserComment

#Constants For TOKEN numbers
$ExifIDColorSpace              = 40961 #  0xA001   
$ExifIDContrast                = 41992 #  0xA408f
$ExifIDExposureMode            = 41986 #  0xA402
$ExifIDExposureProgram         = 34850 #  0x8822
$ExifIDFlash                   = 37385 #  0x9209
$ExifIDLightSource             = 37384 #  0x9208
$ExifIDMeteringMode            = 37383 #  0x9207
$ExifIDSaturation              = 41993 #  0xA409
$ExifIDSceneCaptutreMode       = 41990 #  0xA406
$ExifIDSharpness               = 41994 #  0xA40A
$ExifIDSubjectRange            = 41996 #  0xA40C
$ExifIDWhiteBalance            = 41987 #  0xA403

#Constants for special case ratios
$ExifIDExposuretime            = 33434 #  0x829A
$ExifIDGPSLattitude            = 2
$ExifIDGPSLongitude            = 4

#Constants for normal numbers
$ExifIDDigitalZoomRatio        = 41988 #  0xA404
$ExifIDExpbias                 = 37380 #  0x9204
$ExifIDFNumber                 = 33437 #  0x829D
$ExifIDFocalLength             = 37386 #  0x920A
$ExifIDFocalLengthIn35mmFormat = 41989 #  0xa405
$ExifIDHeight                  = 40963 #  0xA003
$ExifIDISO                     = 34855 #  0x8827
$ExifIDMaxApperture            = 37381 #  0x9205
$ExifIDWidth                   = 40962 #  0xA002
$ExifIDGPSAltitude             = 6
$ExifIDOrientation             = 274   #  0x0112
$ExifIDRating                  = 18246 #  0x4746

#Constants For Byte Arrays
$ExifIDFileSource             = 41728 #  0xA300
$ExifIDMakerNote              = 37500 #  0x927C
$ExifIDGPSVer                 = 0

Function Get-ExifItem {
[CmdletBinding()]
<#
        .Synopsis
            Returns an single item of Generic Exif data
        .Description
            Returns the data part of a single EXIF property item -not the type.
        .Example
            C:\PS> Get-ExifItem -image $image -ExifID $ExifIDModel
            Returns the Camera model string
        .Parameter image
            The image from which the data will be read
        .Parameter ExifID
            The ID of the required data field.
            The module defines constants with names beginning $ExifID for the most used ones.
    #>
  Param  (  [Parameter(ValueFromPipeline=$true)]
            [__ComObject]$image,
            $ExifID
          )
  Process {
    foreach ($id in $exifID) {
        try   {$item = $image.Properties.Item("$ID")  }
        Catch { Write-Verbose "Error getting exif item $ID - probably doesn't exist"  ; continue   }
        if ($item) {
            Write-Verbose "Type is $($item.type)"
            if (($item.Type -eq 1007) -or ($item.Type -eq 1006) )  {                                     # "Rational"=1006;"URational"=1007
                if (($ExifID -eq $ExifIDExposuretime) -and ($item.Value.Numerator -eq 1) ) {"1/$($item.Value.Denominator)"} else {$item.value.value} }
                elseif (($item.type -eq 1101) -or ($item.type -eq 1100)) {$item.value.string() }                                         # "VectorOfByte"=1101
            else {$item.value}
        }
    }
  }
}

Function Get-Exif{
<#
        .Synopsis
            Returns an object containing Exif data
        .Description
            Returns an object containing Exif data
        .Parameter image
            The image from which the data will be read
        .Example
             C:\ps> get-image IMG_1234.JPG | get-exif
             Returns the exif summary for the specified file
        .Example
             C:\ps> Get-exif .\*.JPG | format-table -auto Path, iso,Fnumber,exposuretime
             Gets the exif data for all the files in the current folder
             and returns a table of exposure information.
#>
Param   ( [Parameter(ValueFromPipeline=$true,Mandatory=$true)]$image)
Process {
    if ($image -is [system.io.fileinfo] ) {$image = $image.FullName }
    if ($image -is [String]             ) {$image = Get-Image $image}
    if ($image.count -gt 1              ) {$image | ForEach-Object {Get-Exif $_} ; Return}
    $myvar =[int](Get-ExifItem -image $image -ExifID $ExifIDFlash)
    $flash=""
    If ($myvar –band 1)     {$Flash += "Flash fired"}
    If ($myvar -bAnd 4)     {$Flash += ", return"
                              If ($myvar -bAnd 2) {$flash += " detected"} else {$Flash += "not detected"}
    }
    If ($myvar -bAnd 8)   { If (($myvar-bAnd 16) -eq 16)  {$Flash = "Flash Auto, " + $flash} else {$flash = "Flash on, " + $flash} }
    ElseIf                      ($myvar -bAnd 16)         {$flash = "Flash off. " }
    If ($myvar -bAnd 32)    {$flash =  "No Flash function"    }
    If ($myvar -bAnd 64)    {$flash += ", Red Eye reduction"  }

    $Keywords         = Get-ExifItem -image $image -ExifID $ExifIDKeywords
    if ($keywords) {$keywords = $keywords.Split(";") }

    $gps = ""
    $l=(get-ExifItem -image $image -ExifID $ExifIDGPSLattitude)
    if ($l.count -eq 3) {$gps += "$($l[0].value)°$($l[1].value)'$($l[2].value)"""}
    if ($l.count -eq 2) {$gps += "$($l[0].value)°$($l[1].value)'" }
    $gps = $GPS +=  (get-ExifItem -image $image -ExifID $ExifIDGPSLatRef)
   
    $l=(get-ExifItem -image $image -ExifID $ExifIDGPSLongitude)
    if ($l.count -eq 3) {$gps += "  $($l[0].value)°$($l[1].value)'$($l[2].value)"""}
    if ($l.count -eq 2) {$gps += "  $($l[0].value)°$($l[1].value)'" }
    $gps = $GPS +=  (get-ExifItem -image $image -ExifID $ExifIDGPSLongRef)

    $altref = get-ExifItem -image $image -ExifID $ExifIDGPSAltRef
    if ($altRef -EQ 0) {$gps += ", $(get-ExifItem -image $image -ExifID $ExifIDGPSAltitude)M above Sea Level"}
    if ($altRef -EQ 1) {$gps += ", $(get-ExifItem -image $image -ExifID $ExifIDGPSAltitude)M below Sea Level"}

    $dt = (get-ExifItem -image $image -ExifID $ExifIDDateTimeTaken)
    if ($dt) {$dt = [DateTime]::ParseExact($dt,"yyyy:MM:dd HH:mm:ss",[System.Globalization.CultureInfo]::InvariantCulture) }

    New-Object PSObject -Property @{Flash            =  $flash
                                    Keywords         =  $Keywords 
                                    GPS              =  $GPS
                                    DateTaken        =  $dt
                                    Path             =  $Image.FullName
                                    Manufacturer     =  (Get-ExifItem -image $image -ExifID $ExifIDMake)
                                    Model            =  (Get-ExifItem -image $image -ExifID $ExifIDModel)
                                    Software         =  (Get-ExifItem -image $image -ExifID $ExifIDSoftware)
                                    Subject          =  (Get-ExifItem -image $image -ExifID $ExifIDSubject)
                                    Title            =  (Get-ExifItem -image $image -ExifID $ExifIDTitle)
                                    Comment          =  (Get-ExifItem -image $image -ExifID $ExifIDComment)
                                    Author           =  (Get-ExifItem -image $image -ExifID $ExifIDAuthor)
                                    Copyright        =  (Get-ExifItem -image $image -ExifID $ExifIDCopyright)
                                    Artist           =  (Get-ExifItem -image $image -ExifID $ExifIDArtist)
                                    StarRating       =  (Get-ExifItem -image $image -ExifID $ExifIDRating)
                                    ISO              =  (Get-ExifItem -image $image -ExifID $ExifIDISO)
                                    ExposureBias     =  (Get-ExifItem -image $image -ExifID $ExifIDExpbias)
                                    Exposuretime     =  (Get-ExifItem -image $image -ExifID $ExifIDExposuretime)
                                    FNumber          =  (Get-ExifItem -image $image -ExifID $ExifIDFNumber)
                                    MaxApperture     =  (Get-ExifItem -image $image -ExifID $ExifIDMaxApperture)
                                    FocalLength      =  (Get-ExifItem -image $image -ExifID $ExifIDFocalLength)
                                    FocalLength35mm  =  (Get-ExifItem -image $image -ExifID $ExifIDFocalLengthIn35mmFormat)
                                    DigitalZoomRatio =  (Get-ExifItem -image $image -ExifID $ExifIDDigitalZoomRatio)
                                    Height           =  (Get-ExifItem -image $image -ExifID $ExifIDHeight )
                                    Width            =  (Get-ExifItem -image $image -ExifID $ExifIDWidth)
                                    SubjectRange     =  @{1="Macro"; 2="Close"; 3="Distant"}[[int](      Get-ExifItem -image $image -ExifID $ExifIDSubjectRange)]
                                    ExposureMode     =  @{0="Auto"; 1="Manual"; 2="Auto Bracket"}[[int]( Get-ExifItem -image $image -ExifID $ExifIDExposureMode)]
                                    WhiteBalance     =  @{0="Auto"; 1="Manual" }[[int](                  Get-ExifItem -image $image -ExifID $ExifIDWhiteBalance)]
                                    Contrast         =  @{0="Normal"; 1="Soft"; 2="Hard" }[[int](        Get-ExifItem -image $image -ExifID $ExifIDContrast)]
                                    Sharpness        =  @{0="Normal"; 1="Soft"; 2="Hard" }[[int](        Get-ExifItem -image $image -ExifID $ExifIDSharpness)]
                                    Saturation       =  @{0="Normal"; 1="Low"; 2 ="High"}[[int](         Get-ExifItem -image $image -ExifID $ExifIDSaturation)]   
                                    Orientation      =  @{1="0"; 3="180"; 6="270"; 8="90"}[[int](        Get-ExifItem -image $image -ExifID $ExifIDOrientation) ]  # (0 -=Row 0 is Top, Col 0 is left / 180=Inverted, Row 0 Bottom and col 0 is Right / 270=90 Degrees CounterClockWise, Row 0 is right and col 0 is top / 90=90 Degrees ClockWise, row 0 is left, Col 0 is bottom
                                    ColorSpace       =  @{1="sRGB"; 2="Adobe RGB" }[[int](               Get-ExifItem -image $image -ExifID $ExifIDColorSpace) ] #'(the value of 2 is not standard EXIF. Instead, an Adobe RGB image is indicated by "Uncalibrated" with an InteropIndex of "R03"')
                                    FileSource       =  @{1="Film scanner"; 2="Print scanner"; 3="Digital still camera"}[[int](                Get-ExifItem -image $image -ExifID $ExifIDFileSource)]
                                    CaptureMode      =  @{0="Standard"; 1="Landscape"; 2="Portrait"; 3="NightScene"}[[int](                    Get-ExifItem -image $image -ExifID $ExifIDSceneCaptutreMode)]
                                    MeteringMode     =  @{1="Av"; 2="Centre"; 3="Spot"; 4="Multi-Spot"; 5="Multi-Segment"; 6="Partial"}[[int]( Get-ExifItem -image $image -ExifID $ExifIDMeteringMode)]
                                    ExposureProgram  =  @{1="Manual"; 2="Program: Normal"; 3="Aperture Priority"; 4="Shutter Priority"; 5="Program: Creative"; 6="Program: Action";  7="Portrait Mode"; 8="Landscape Mode"}[[int]( Get-ExifItem -image $image -ExifID $ExifIDExposureProgram)] # Manual includes  Bulb, X-Sync Mode  Pentax Sv Mode and TAv mode report 0 - unknown.  Creative is  Depth of field Biased and Action is shutter biased
                                    LightSource      =  @{0="Auto";  1="Daylight"; 2="Fluorescent";  3="Tungsten"; 4="Flash"; 9="Fine Weather"; 10="Cloudy Weather"; 11="Shade"; 12="Daylight Fluorescent"; 13="Day White Fluorescent"; 14="Cool White Fluorescent"; 15="White Fluorescent"; 17="Standard Light A"; 18="Standard Light B"; 19="Standard Light C"; 20="D55"; 21="D65"; 22="D75"; 23="D50"; 24="ISO Studio Tungsten"}[[int]( Get-ExifItem -image $image -ExifID $ExifIDLightSource)]
                                    }
  }
}

#requires -version 2.0
function Get-Image {
    <#
        .Synopsis
            Returns an image object for a file
        .Description
            Uses the Windows Image Acquisition COM object to get image data
        .Example
            Get-ChildItem $env:UserProfile\Pictures -Recurse | Get-Image       
        .Parameter file
            The file to get an image from
    #>
    param(   
    [Parameter(ValueFromPipelineByPropertyName=$true,Mandatory=$true)]
    [Alias('FullName',"FileName")]
    [ValidateScript({Test-path $_ })][string]$Path)
   
    process {
        foreach ($file in (resolve-path -Path $path) ) {
            $image  = New-Object -ComObject Wia.ImageFile       
            try {       
                Write-Verbose "Loading file $($realItem.FullName)"
                $image.LoadFile($file.path)
                $image |
                    Add-Member NoteProperty FullName $File -PassThru |
                    Add-Member ScriptMethod Resize {
                        param($width, $height, [switch]$DoNotPreserveAspectRatio)                   
                        $image = New-Object -ComObject Wia.ImageFile
                        $image.LoadFile($this.FullName)
                        $filter = Add-ScaleFilter @psBoundParameters -passThru -image $image
                        $image = $image | Set-ImageFilter -filter $filter -passThru
                        Remove-Item $this.Fullname
                        $image.SaveFile($this.FullName)                   
                    } -PassThru |
                    Add-Member ScriptMethod Crop {
                        param([Double]$left, [Double]$top, [Double]$right, [Double]$bottom)
                        $image = New-Object -ComObject Wia.ImageFile
                        $image.LoadFile($this.FullName)
                        $filter = Add-CropFilter @psBoundParameters -passThru -image $image
                        $image = $image | Set-ImageFilter -filter $filter -passThru
                        Remove-Item $this.Fullname
                        $image.SaveFile($this.FullName)                   
                    } -PassThru |
                    Add-Member ScriptMethod FlipVertical {
                        $image = New-Object -ComObject Wia.ImageFile
                        $image.LoadFile($this.FullName)
                        $filter = Add-RotateFlipFilter -flipVertical -passThru
                        $image = $image | Set-ImageFilter -filter $filter -passThru
                        Remove-Item $this.Fullname
                        $image.SaveFile($this.FullName)                   
                    } -PassThru |
                    Add-Member ScriptMethod FlipHorizontal {
                        $image = New-Object -ComObject Wia.ImageFile
                        $image.LoadFile($this.FullName)
                        $filter = Add-RotateFlipFilter -flipHorizontal -passThru
                        $image = $image | Set-ImageFilter -filter $filter -passThru
                        Remove-Item $this.Fullname
                        $image.SaveFile($this.FullName)                   
                    } -PassThru |
                    Add-Member ScriptMethod RotateClockwise {
                        $image = New-Object -ComObject Wia.ImageFile
                        $image.LoadFile($this.FullName)
                        $filter = Add-RotateFlipFilter -angle 90 -passThru
                        $image = $image | Set-ImageFilter -filter $filter -passThru
                        Remove-Item $this.Fullname
                        $image.SaveFile($this.FullName)                   
                    } -PassThru |
                    Add-Member ScriptMethod RotateCounterClockwise {
                        $image = New-Object -ComObject Wia.ImageFile
                        $image.LoadFile($this.FullName)
                        $filter = Add-RotateFlipFilter -angle 270 -passThru
                        $image = $image | Set-ImageFilter -filter $filter -passThru
                        Remove-Item $this.Fullname
                        $image.SaveFile($this.FullName)                   
                    } -PassThru
                   
            } catch {
                Write-Verbose $_
            }
        }     
    }   
}


I then wrote this small Power Shell script which walks through all of single-level-deep subdirectories of a master directory.  It looks for string "29-1103" in the EXIF data, which in my case indicated that the image hadn't been edited by Photoshop and had the makernotes attached.  If that string was seen, then I use exiftool to delete the makernotes.  This worked wonderfully on thousands of images, just updating the ones that needed to be updated.  In reality I probably could have just did a "-makernotes" on *.jpg for each directory, but I didn't think of that until I had written this.  Oh well, use it as you may!

-- Geoff

Code Select Expand


$dirs = @(dir -Path "G:\top-level-dir")
foreach ($dir in $dirs) {
    if ($dir.GetType().FullName -eq 'System.IO.DirectoryInfo') {
      $path_jpg = $dir.FullName + "\*.jpg"
      $files = @(dir $path_jpg)
      foreach ($file in $files) {
          $software = @(Get-exif $file) | Select-String "29-1103"
          if ($software) {
              $command = '"-makernotes=" ' + $file
              echo $command
              &exiftool $command
          }
      }
    }