PCB Inspector with pytrack

One of my friends gently asked me to help them on automatic inspection of PCBs (xray).

I used pytrack to investigate and report soldering failures (bad bubbles). 

# -*- coding: utf-8 -*-

# 07.05.2017

# porsuk

from __future__ import division, unicode_literals, print_function  # for compatibility with Python 2 and 3

import matplotlib as mpl

import matplotlib.pyplot as plt

import numpy as np

import pandas as pd

from pandas import DataFrame, Series  # for convenience

from scipy import ndimage

from skimage import morphology, util, filters

import pims

import trackpy as tp

def crop(img):

    """

    Crop the image to select the region of interest

    """

    x_min = 20#745

    x_max = -25#850

    y_min = 50#225

    y_max = -250#300

    

    return img[y_min:y_max,x_min:x_max]

def rgb2gray(rgb):

    r, g, b = rgb[:,:,0], rgb[:,:,1], rgb[:,:,2]

    gray = 0.2989 * r + 0.5870 * g + 0.1140 * b

    return gray

def preprocess_pcb(img):

    img=rgb2gray(img)

    """

    Apply image processing functions to return a binary image

    """

    # Crop the pictures as for raw images.

    img = crop(img)

    print(img)

    # Apply thresholds

    img = filters.threshold_adaptive(img, 57)

    threshold = 0.9

    idx = img > img.max() * threshold

    idx2 = img < img.max() * threshold

    img[idx] = 0

    img[idx2] = 3

    img = ndimage.binary_dilation(img)

    img = ndimage.binary_dilation(img)

    return util.img_as_int(img)

frames = pims.ImageSequence('*.jpg',process_func=preprocess_pcb)

for frame in frames:

     f = tp.locate(frame, percentile=10,diameter=77, minmass= 3.0e+07,separation=80,threshold=1/30)

     print('frame = ',f['frame'][0] )

     print(f)

     print('max bubble percentage: ', 20 * max(f['size']) / 250 )

     plt.figure(f['frame'][0])  # make a new figure

     tp.annotate(f,frame,plot_style={'markersize':35});