3dhisto.py

gistfile1.py

import cv2
import numpy as np
from matplotlib import pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm
from matplotlib.ticker import LinearLocator, FormatStrFormatter


def processStream(fname):
    cap = cv2.VideoCapture(fname)

    bright = []
    frames = 0
    while(cap.isOpened()):
        ret, frame = cap.read()

        if ret:
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

            r = cv2.calcHist([gray], [0], None, [256],[0,256])
            cv2.normalize(r, r, 0, 255, cv2.NORM_MINMAX)

            frames += 1
            if frames > 50:
                bright.append(np.ravel(r))
                frames = 0
        else:
            break

    cap.release()

    y = np.arange(0, len(bright), 1)
    x = np.arange(0, 256, 1)
    x, y = np.meshgrid(x, y)

    z = np.array(bright)

    for rn, row in enumerate(z):
        if (rn > 5) and (rn < len(z)-5):
            for cn, col in enumerate(row):
                if (cn > 5) and (cn < len(row)-5):
                    zf = [i[cn-5:cn+5] for i in z[rn-5:rn+5]]
                    z[rn][cn] = np.mean(zf)
                else:
                    z[rn][cn] = 0
        else:
            for cn, col in enumerate(row):
                z[rn][cn] = 0

    fig = plt.figure()
    ax = fig.gca(projection='3d')
    surf = ax.plot_surface(x, y, z, rstride=10, cstride=10, cmap=cm.coolwarm, linewidth=0)
    ax.set_ylim(0, len(bright))
    ax.set_xlim(0, 256)
    ax.set_xlabel('Luminosity')
    ax.set_zlabel('Frequency')
    ax.set_ylabel('Time')
    ax.zaxis.set_major_formatter(FormatStrFormatter('%d'))
    fig.colorbar(surf, shrink=0.5, aspect=5)
    plt.show()