Raster to polygon script loop failing!! error 99999!

I am trying to make a script which selects every .png file in a folder beginning with the letters "LG". I then want the scipt create a shapefile, replacing the "LG" with "SH", and then i want the script to buffer that shapefile and rename the buffer with the first 2 letters being "SB"!

I keep getting an error 99999 error message at line 37!

( gp.RasterToPolygon_conversion(INPUT_RASTER, Output_polygon_features, "SIMPLIFY", "VALUE") )

Can anyone see why this isnt working? I am very, very new to this and have been staring at this script pulling out my hair for days!!

Here is the script:

# Load required toolboxes...
gp.AddToolbox("C:/Program Files/ArcGIS/ArcToolbox/Toolboxes/Conversion Tools.tbx")
gp.AddToolbox("C:/Program Files/ArcGIS/ArcToolbox/Toolboxes/Analysis Tools.tbx")

# Script arguments...

folder = "D:\\J04-0083\\IMAGEFILES"
for root, dirs, filenames in os.walk(folder): # returms root, dirs, and files
    for filename in filenames:
        filename_split =开发者_StackOverflow中文版 os.path.splitext(filename) # filename and extensionname (extension in [1])
        filename_zero = filename_split[0]

        try:
            first_2_letters = filename_zero[0] + filename_zero[1]
        except:
            first_2_letters = "XX"

        if first_2_letters == "LG":
            Output_polygon_features = "D:\\J04-0083\\ShapeFiles.gdb\\" + "SH_" + filename + ".shp"

            # Process: Raster to Polygon...

            INPUT_RASTER = os.path.join(root + "\\" + filename_zero + ".png")
            gp.RasterToPolygon_conversion(INPUT_RASTER, Output_polygon_features, "SIMPLIFY", "VALUE") 

            Distance__value_or_field_ = "5 Meters"
            Raster_Buffer_shp = "SB_" + filename + ".shp"

            # Process: Buffer...
            gp.Buffer_analysis(Output_polygon_features, Raster_Buffer_shp, Distance__value_or_field_, "FULL", "ROUND", "NONE", "")

Is .png the format that this function wants? PNG is a compressed format so I would think that something like this would be expecting an uncompressed format. In fact, since the name of the function is RasterToPolygon_conversion, wouldn't the function be expecting a raster format? The docs say that the input should be an integer raster dataset. In addition, The input raster can have any cell size and may be any valid integer raster dataset. Anyway, I suspect that is the real problem.

The last thing to check, if the file is in the correct format as per above, is if there is a field VALUE in the file.

try using a GRID or TIFF file instead of a PNG. You can convert the PNG with: http://webhelp.esri.com/arcgiSDEsktop/9.3/index.cfm?TopicName=raster_to_other_format_(multiple)_(conversion)

and then process it's output into the Raster to Polygon conversion.

You could also check the file path of the INPUT RASTER to make sure it looks correct by:

INPUT_RASTER = os.path.join(root + "\\" + filename_zero + ".png")
print INPUT_RASTER
gp.RasterToPolygon_conversion(INPUT_RASTER, Output_polygon_features, "SIMPLIFY", "VALUE") 

There is also a method of building a filepath by:

import os
root + os.sep + filename_zero + '.png'