Python extension causing an error with numpy

[arkane]

Hello, I have written some python extensions and it seems to be causing a TypeError with numpy.

Here is my code:

import Image, os, sys, gc, numpy, math
sys.path.append("/home/halon/pyxtn")

import spam2


def LoadImages(start, y_stop):
    """Open .tif images, append data to list."""
    global image_data_list, number_of_channels

    for i in range(0, number_of_channels):
        
        if i > 0:
            _file= start
            new_channel= '_ch0'+str(i)
            index= _file.index('_ch')
            old_channel= _file[index:index+5]
            _file= _file.replace(old_channel,new_channel)
            
        else:
            _file= start

        image= Image.open(_file)
        image_data_list[i].append(list(image.getdata()))

        _file, next_slice= YIncrement(y_stop, _file)

        while True:
            if next_slice== y_stop:
                image= Image.open(_file)
                image_data_list[i].append(list(image.getdata()))
                break
            else:
                image= Image.open(_file)
                image_data_list[i].append(list(image.getdata()))
                _file, next_slice= YIncrement(y_stop, _file)
                
    
        
def YIncrement(y_stop, file_name):
    """Incement to the next y slice"""

    index= file_name.index('_y')
    old= file_name[index:index+5]
    number= old[2:5]
    
    if number[0]== "0" and number[1]== "0":
        number= int(number[2])
    elif number[0]== "0" and number[1]!= "0":
        number= int(number[1]+number[2])
    else:
        number= int(number)
  
    number= str(number+1)
              
    if len(number)== 1:
        y_slice= "_y00"+ number
    
    elif len(number)== 2:
        y_slice= "_y0"+ number

    else:
        y_slice= "_y"+ number

    _file= file_name.replace(old,y_slice)

    return _file, y_slice


directory= "/home/halon/4pi2"
os.chdir(directory)

#Image dimensions
max_x= 512
max_z= 450
max_y= 341
number_of_channels= 1

#Name of first and last files in image stack
start= "2007_10_04_SYCP3_MLH1_Stack01_deconv_both_y000_ch00.tif"
stop= "2007_10_04_SYCP3_MLH1_Stack01_deconv_both_y050_ch00.tif"

index= stop.index('_y')
y_stop= stop[index:index+5]

image_data_list= [[]]

LoadImages(start, y_stop)
print "Images loaded..."

print "Smothing data..."
for i in range(0, len(image_data_list[0])):

    image_data= image_data_list[0][i]
    
    smoothed_data= spam2.Blur_2D(image_data)
    smoothed_data= spam2.Blur_2D(smoothed_data)
    smoothed_data= spam2.Blur_2D(smoothed_data)

    image_data_list[0][i]= smoothed_data
    
i= 0 
for image_data in image_data_list[0]:
    max_val= max(image_data)
    limit= spam2.Limit(image_data, 1000, max_val)
    mask= spam2.Threshold(image_data,18)

    image_array= numpy.zeros((max_z,max_x,3),numpy.uint8)


    for x in range(0, max_x):
        for z in range(0, max_z):
            if mask[x+ z*max_x]== 1:
                image_array[x,z]= [255,255,255]
                     
          
    filename= "image"+str(i)+".png"
    image= Image.fromarray(image_array,"RGB")
    image.save(filename)
    i= i+1

When I run this code, the function call on line 105 produces the following error:

Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "big.py", line 108, in <module>
TypeError: an integer is required

If I comment out line 105, everything is fine. Here is the C code for the function Limit:

//Called from Python as Limit//
static PyObject
*Average(PyObject *self, PyObject *args){

  PyObject *input_list, *mask_size, *list_max;
  
  int i, input_list_size, counter, *histogram;
  long sum= 0, max_val, pix_val, pix_in_mask;
  float threshold;

  if(!PyArg_ParseTuple(args, "OOO", &input_list, &mask_size, &list_max))
    return NULL;

  input_list_size= PyList_Size(input_list);
  pix_in_mask= PyInt_AsLong(mask_size);
  max_val= PyInt_AsLong(list_max);

  histogram= malloc(256*sizeof(int));
  
  for(i= 0; i<= 255; i++) histogram[i]= 0;

  for(i= 0; i<= input_list_size; i++){
    pix_val= PyInt_AsLong(PyList_GetItem(input_list,i));
    
    if(pix_val >0)
        histogram[pix_val]++;
  }

  counter= 0;
  i= 255;

  do{
    counter += histogram[i];
    i--;
  
  } while((counter < pix_in_mask)&&(i>0));
  
  threshold= (float)i /255.;

  return Py_BuildValue("f", threshold);

}

Any help is appreciated!!!!! Thanks.