Code for TIFF export

Function ExportGreyScaleTIFF (datawave, ExportPath)
    wave DataWave  //reference to a 2 or 3d wave with greyscale information
    String ExportPath //contains the name of an Igor Path where the file will be saved
   
    //make sure the wave exists
    if (!(WaveExists (dataWave)))
        doAlert 0, "Sorry, but the wave, " + nameofwave (datawave) + ", does not exist."
        return 1
    endif
   
    //Check the path
    PathInfo $ExportPath
    if (V_Flag == 0)
        if ((cmpStr (ExportPath, "")) == 0)
            ExportPath = "ExportPath"
        endif
        NewPath /M="Where do you want to save the TIFF?" /O/Q ExportPath
        if (V_Flag) // User cancelled the dialog to make new path
            return 1
        endif
    endif
   
    //check wave diminsions. 1D and 4D waves are no-go.
    variable imdims = wavedims (datawave)
    if (imdims == 1)       
        doalert 0, "Sorry, but you need an image or an image stack to write a tiff file."
        return 1
    else
        if (imdims == 4)
            doalert 0, "Sorry, but this procedure hasn't been extended to 4 dimensions yet"
            return 1
        endif
    endif
   
    // No Complex waves
    if (WaveType(Datawave) & 0x01)
        doalert 0, "Sorry, but this procedure doesn't do complex waves."
        return 1
    endif
   
    //Make a name for the exported tiff from the wavename plus the tif extension
    String FileNameStr = nameofwave (datawave) + ".TIF"
    // Check the file name/location for existence
    FileNameStr = CheckFileOnDisk (ExportPath, FileNameStr)
    if ((cmpstr (FileNameStr, "")) == 0)
        return 1
    endif
       
    //define some variables and find out some information about the image,
       // also make a temp wave of right bit depth to hold a plane of the wave
    variable ii             // used for iterations
    variable temp           // a variable used to hold various values temporarily while writing to the file
    variable imwidth = dimsize (datawave, 0)  // the width of the image, in pixels
    variable imlength=dimsize (datawave, 1) // the length of the image, in pixels
    variable imdepth  = max (1, dimsize (datawave, 2))// the image depth, i.e., number of planes
    variable  sampleBits // number of bits/per sample (8, 16, or 32)
    variable sampleFormat  // Sample Format 1 = unsigned integer data,
                                          // 2 = two’s complement signed integer data ,3 = IEEE floating point data [IEEE]

    if (!(datafolderExists ("root:packages:")))
        newdatafolder root:packages
    endif
    if (WaveType (Datawave) & 0x04) // 64 bit floating point
        SampleBits = 64
        make/o/D/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
    elseif (WaveType (DataWave) & 0x02) // 32 bit floating point
        sampleBits = 32
        make/o/s/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
    elseif  (WaveType (DataWave) & 0x20)  // 32 bit integer
        sampleBits = 32
        if (WaveType(datawave) & 0x40) // unsigned
            SampleFormat = 1
            make/I/u/o/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
        else
            SampleFormat = 2 // signed
            make/I/o/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
        endif
    elseif (WaveType(datawave) & 0x10)  // 16 bit integer
        sampleBits = 16
        if (WaveType(datawave) & 0x40) // unsigned
            SampleFormat = 1
            make/W/u/o/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
        else
            SampleFormat = 2 // signed
            make/W/o/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
        endif
    elseif (WaveType(datawave) & 0x08) // 8 bit integer
        sampleBits = 8
        if (WaveType(datawave) & 0x40) // unsigned
            SampleFormat = 1
            make/B/u/o/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
        else
            SampleFormat = 2 // signed
            make/B/o/n= ((imwidth), (imlength)) root:Packages:aTIFFplane
        endif
    else
        doalert 0, "Sorry, but the data type of the wave, " + nameofwave (dataWave) + ", was not recognized."
        return 1
    endif
    WAVE aplane =  root:Packages:aTIFFplane
    variable imBytes =  imwidth * imlength * (sampleBits/8) // the number of bytes in an individual image plane
    string byteOrderStr   // MM for Macintosh, II for intel; we will write native byte order
                                          // for the platform we are running on
    if ((cmpstr (IgorInfo(2), "Macintosh")) == 0)
        byteOrderStr = "MM"
    else
        byteOrderStr = "II"
    endif

    // Open a new file in the export path directory
    variable daRefNum  // reference number of the file we will open
    Open/P=ExportPath/T= "TIFF"  darefNum  as FileNameStr
   
    // first write the byte order string and the magic 42, in two bytes each
    FBinWrite darefNum, byteOrderStr
    temp = 42
    FBinWrite /F=2/U darefNum, temp
   
    //write offset to the first IFD unsigned 4 bytes, it will be after this 8 bit header, so 8
    temp = 8
    FBinWrite /F=3/U darefNum, temp
   
    //Iterate through each plane in the image, making an image file directory and writing the plane
    // Thus, IFDs and images alternate in the file. One could make a TIFF file with the IFDs all at the start, or
    // any other way you like, this just seemed simplest to me.
    For (ii = 0; ii < imdepth; ii += 1)
        //write the IFD - start with 2 byte count of number of directories
        temp = 10
        FBinWrite /F=2/U darefNum, temp
   
        temp = 256      //tag 256 = image width
        FBinWrite /F=2 darefNum, temp
        temp = 4    // Field type 4byte unsihned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    // number of values = 1
        FBinWrite /F=3/U darefNum, temp
        FBinWrite /F=3/U darefNum, imwidth
   
        temp = 257      // tag 257 = image length
        FBinWrite /F=2 darefNum, temp
        temp = 4    // Field type 4byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1 // number of values = 1
        FBinWrite /F=3/U darefNum, temp
        FBinWrite /F=3/U darefNum, imlength
   
        temp = 258      // tag258 = bits/sample
        FBinWrite /F=2 darefNum, temp
        temp = 3    // Field type 2 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    // number of values = 1
        FBinWrite /F=3/U darefNum, temp
        temp = sampleBits   // number of bits per sample
        FBinWrite /F=2/U darefNum, temp
        temp = 0    // need to pad with 0
        FBinWrite /F=2/U darefNum, temp
   
        temp = 259      // tag259 = compression
        FBinWrite /F=2 darefNum, temp
        temp = 3  // Field type 2 byte unsigned integer
        FBinWrite /F=2 darefNum, temp
        temp = 1 // number of values = 1
        FBinWrite /F=3/U darefNum, temp
        temp = 1    // No compression
        FBinWrite /F=2 darefNum, temp
        temp = 0    // need to pad with 0
        FBinWrite /F=2/U darefNum, temp
   
        temp = 262      // tag262 = photometric interpretation
        FBinWrite /F=2 darefNum, temp
        temp = 3        // Field type 2 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    //number of values = 1
        FBinWrite /F=3/U darefNum, temp
        temp = 1    // black is 0, max value is white
        FBinWrite /F=2/U darefNum, temp
        temp = 0    // need to pad with 0
        FBinWrite /F=2/U darefNum, temp
   
        temp = 273      // tag 273 = strip offsets, we will only make 1 strip, so there is only one offset
        FBinWrite /F=2 darefNum, temp
        temp = 4    // Field type 4 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    //number of values = 1
        FBinWrite /F=3/U darefNum, temp
        temp = 134  + ((126+ imBytes) * ii)// The image starts immediatley after this IFD.
                                                                    // Initial header is 8 bytes, an IFD is 126 bytes
        FBinWrite /F=3/U darefNum, temp
   
        temp = 277      // tag 277 = samples/pixel
        FBinWrite /F=2 darefNum, temp
        temp = 3    // Field type 2 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    // number of values = 1
        FBinWrite /F=3/U darefNum, temp
        temp = 1    // 1 sample/pixel, i.e., greyscale image
        FBinWrite /F=2 darefNum, temp
        temp = 0    // need to pad with 0
        FBinWrite /F=2/U darefNum, temp
   
        temp = 278      // tag278 = rows/strip we only make 1 strip/image, so this is the same as rows
        FBinWrite /F=2 darefNum, temp
        temp = 3    // Field type 2 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1
        FBinWrite /F=3/U darefNum, temp
        temp = imlength //1 strip/image, so this is the same as rows
        FBinWrite /F=2/U darefNum, temp
        temp = 0    // need to pad with 0
        FBinWrite /F=2/U darefNum, temp
   
        temp = 279      // tag279 = strip bytecounts (number of bytes in each strip, after compresion)
        FBinWrite /F=2 darefNum, temp
        temp = 4    // Field type 4 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    // number of values  = 1
        FBinWrite /F=3/U darefNum, temp
        FBinWrite /F=3/U darefNum, imBytes  // only 1 strip, so byte count is same as bytes in an image
       
        temp = 339      // tag339 = Data Sample Format
        FBinWrite /F=2 darefNum, temp
        temp = 3        // Field type 2 byte unsigned integer
        FBinWrite /F=2/U darefNum, temp
        temp = 1    // number of samples = 1
        FBinWrite /F=3/U darefNum, temp
        FBinWrite /F=2 darefNum, sampleFormat
        temp = 0    // need to pad with 0
        FBinWrite /F=2/U darefNum, temp

        // Last thing in the IFD is 4 bytes for offset to start of next IFD (it will be right after the image),
                //unless it's the last image plane, when 4 bytes of 0 suffice
        if (ii < imdepth-1)
            temp = 8 +  ((126 +imBytes) * (ii + 1))
        else
            temp= 0
        endif
        FBinWrite/F=3 darefnum, temp
               
        // finally, write the image plane
        aplane = datawave [p] [q] [ii]
        FBinWrite /f =0 darefNum,aplane
    endfor
    //Clean up
    close darefnum
    killwaves/z aplane
    return 0
end