export grayscale to raw

#!/usr/bin/env python
from gimpfu import *

def exportToRawFile( image, layer ):
    if( 1 != image.base_type ):
        pdb.gimp_message( "Image is not grayscale.  Leaving" )
        return

    pdb.gimp_plugin_enable_precision();

    try:
        # Create a layer based on what is visible.
        tempLayer = pdb.gimp_layer_new_from_visible( image, image, "Visible" )
        image.add_layer( tempLayer, 0 )

        # Calculate the number of tiles.
        numTiles_Horiz = int(tempLayer.width / 64)
        if( tempLayer.width % 64 > 0 ):
            numTiles_Horiz += 1
        numTiles_Vert = int(tempLayer.height / 64)
        if( tempLayer.height % 64 > 0 ):
            numTiles_Vert += 1

        # Iterate over the tiles.
        pixelByteArray= [];
        debugStr = "";
        for i in range(numTiles_Horiz):
            for j in range(numTiles_Vert):
                # Update the progress bar.
                gimp.progress_update( float(i*numTiles_Vert + j) / float(numTiles_Horiz*numTiles_Vert) )

                # Get the source tile.
                srcTile = tempLayer.get_tile( False, j, i )

                # Iterate over the pixels of each tile.
                for y in range(srcTile.eheight):
                    for x in range(srcTile.ewidth):
                        # Get the pixel value.
                        pixel = srcTile[x,y]

                        # Build color value from bytes.
                        colorVal = 0
                        numBytes = int(len(pixel)*0.5)  # divide by 2 to skip the alpha channel
                        for idx in range(numBytes):
                            pixelByteArray.append( ord(pixel[idx]) )
                            byteHexVal = ord(pixel[idx]) << (idx*8)
                            colorVal += byteHexVal

                        debugStr += "pixel ({0},{1}): {2} (0x{2:x})\r\n".format( x, y, colorVal )

        pdb.gimp_message( debugStr )

        # Remove the temp layer.
        image.remove_layer( tempLayer )

        # Output pixel values to file.
        if "[Untitled]" != image.name:
            filePath = os.path.splitext( image.filename )[0] + ".raw"
            outputFile = open( filePath, 'wb' )
            outputFile.write( bytearray(pixelByteArray) )
            outputFile.close()
            pdb.gimp_message( "Written out to file {0}".format(filePath) )
        else:
            pdb.gimp_message( "You must save this project first." )

    except Exception as err:
        pdb.gimp_message( "Unexpected error: " + str(err) )

    # End progress.
    pdb.gimp_progress_end()

    return

register(
    "python_fu_export_raw_file",
    "Export to Raw",
    "Export the image to a raw file.",
    "Me",
    "Me",
    "2015",
    "<Image>/MyScripts/Export to RAW",
    "*",
    [],
    [],
    exportToRawFile,
)

main()