GoPiGo - Raspberry Pi Robot

The GoPiGo is a complete kit to build your own robot car. GoPiGo works at the level you’re at — whether you are a parent looking for a smart, fun weekend project to do with your kid, a teacher looking for a way to increase engagement in your science course, or a grad student in need of a platform for your robotics research that requires mobility.

link: http://www.dexterindustries.com/gopigo/

BeagleBone Black Cookbook

Over 70 recipes and solutions for inventors, makers, and budding engineers to create projects using the BeagleBone Black

BeagleBone Black Cookbook
About This Book

• Learn how to develop applications with the BeagleBone Black and open source Linux software
• Sharpen your expertise in making sophisticated electronic devices
• Explore the BeagleBone Black with this easy-to-succeed recipe format

Who This Book Is For
If you are a hardware, Linux, and/or microcomputing novice, or someone who wants more power and possibilities with product prototypes, electronic art projects, or embedded computing experiments, then this book is for you. It is for Internet of Things enthusiasts who want to use more sophisticated hardware than the Raspberry Pi or the Arduino can provide.

Whether you are an engineering student, a DIYer, an inventor, or an advanced electronics enthusiast, this book delivers accessible, compelling instructions for using an advanced microcomputing platform.

What You Will Learn

• Set up and run the BeagleBone Black for the first time
• Learn the basics of microcomputing and Linux using the command line and easy kernel mods
• Make introductory projects with Python, JavaScript, BoneScript, and Node.js
• Explore physical computing and simple circuits using buttons, LEDs, sensors, and motors
• Discover the unique features of the BeagleBone Black and its real-time computing functions
• Build intermediate level audio and video applications
• Assemble draft prototypes for wearable and Internet of Things devices

In Detail
With dozens of how-tos, this book kicks off with the basic steps for setting up and running the BeagleBone Black for the first time, from connecting the necessary hardware and using the command line with Linux commands to installing new software and controlling your system remotely. Following these recipes, more advanced examples take you through scripting, debugging, and working with software source files, eventually working with the Linux kernel. Subsequently, you will learn how to exploit the board's real-time functions. We will then discover exciting methods for using sound and video with the system before marching forward into an exploration of recipes for building Internet of Things projects. Finally, the book finishes with a dramatic arc upward into outer space, when you explore ways to set up test recipes for building a project on board a small satellite's payload.

Style and approach
This comprehensive recipe book deconstructs a complex, often confusing piece of technology, and transforms it to become accessible and fun with snappy, unintimidating prose, and extensive easy-to-succeed instructions.

Python to capture image from Pi Camera Module, with image effects

picamera.camera Module provide function to apply various image effect. This example modified from previous post "Python to capture image from Pi Camera Module, with White Balance setting", to add feature to apply image effect.

reference: API - picamera.camera Module - image_effect


myPiCam.py

import picamera
import Tkinter as tk
import ttk
import time
from PIL import ImageTk, Image
from threading import Thread
import io
import sys
from pkg_resources import require

RQS_0=0
RQS_QUIT=1
RQS_CAPTURE=2
rqs=RQS_0
rqsUpdateSetting=True

def camHandler():
    global rqs
    rqs = RQS_0
    
    camera = picamera.PiCamera()
    #stream = io.BytesIO()

    #set default
    camera.sharpness = 0
    camera.contrast = 0
    camera.brightness = 50
    camera.saturation = 0
    camera.ISO = 0
    camera.video_stabilization = False
    camera.exposure_compensation = 0
    camera.exposure_mode = 'auto'
    camera.meter_mode = 'average'
    camera.awb_mode = 'auto'
    camera.image_effect = 'none'
    camera.color_effects = None
    #camera.rotation = 0
    camera.rotation = 270
    camera.hflip = False
    camera.vflip = False
    camera.crop = (0.0, 0.0, 1.0, 1.0)
    #camera.resolution = (1024, 768)
    camera.resolution = (400, 300)
    #end of set default
    #camera.start_preview()

    while rqs != RQS_QUIT:
        #check if need update setting
        global rqsUpdateSetting
        if rqsUpdateSetting == True:
            rqsUpdateSetting = False
            camera.sharpness = scaleSharpness.get()
            camera.contrast = scaleContrast.get()
            camera.brightness = scaleBrightness.get()
            camera.saturation = scaleSaturation.get()
            camera.exposure_compensation = scaleExpCompensation.get()

            awb_mode_setting = varAwbMode.get()
            labelAwbVar.set(awb_mode_setting)
            camera.awb_mode = awb_mode_setting

            if awb_mode_setting == "off":
                gr = scaleGainRed.get()
                gb = scaleGainBlue.get()
                gAwb = (gr, gb)
                camera.awb_gains = gAwb
                labelAwbVar.set(awb_mode_setting + " : "
                    + str(gAwb))

            image_effect_setting = varImageEffect.get()
            labelImageEffectVar.set(image_effect_setting)
            camera.image_effect = image_effect_setting

            if image_effect_setting == 'solarize':
                if cbSolarize_yuv_Var.get():
                    yuv = 1
                else:
                    yuv = 0
                solarize_para = (
                    yuv,
                    scSolarize_x0_Var.get(),
                    scSolarize_y0_Var.get(),
                    scSolarize_y1_Var.get(),
                    scSolarize_y2_Var.get())
                labelImageEffectVar.set(image_effect_setting + " " + str(solarize_para))
                camera.image_effect_params = solarize_para
            elif image_effect_setting == 'colorpoint':
                camera.image_effect_params = quadrantVar.get()
                labelImageEffectVar.set(image_effect_setting + " " + str(quadrantVar.get()))
            elif image_effect_setting == 'colorbalance':
                colorbalance_para = (
                    scColorbalance_lens_Var.get(),
                    scColorbalance_r_Var.get(),
                    scColorbalance_g_Var.get(),
                    scColorbalance_b_Var.get(),
                    scColorbalance_u_Var.get(),
                    scColorbalance_v_Var.get())
                labelImageEffectVar.set(image_effect_setting + " " + str(colorbalance_para))
                camera.image_effect_params = colorbalance_para
            elif image_effect_setting == 'colorswap':
                labelImageEffectVar.set(image_effect_setting + " " + str(cbColorswap_dir_Var.get()))
                camera.image_effect_params = cbColorswap_dir_Var.get()
            elif image_effect_setting == 'posterise':
                labelImageEffectVar.set(image_effect_setting + " " + str(scPosterise_steps_Var.get()))
                camera.image_effect_params = scPosterise_steps_Var.get()
            elif image_effect_setting == 'blur':
                labelImageEffectVar.set(image_effect_setting + " " + str(scBlur_size_Var.get()))
                camera.image_effect_params = scBlur_size_Var.get()
            elif image_effect_setting == 'film':
                film_para = (
                    scFilm_strength_Var.get(),
                    scFilm_u_Var.get(),
                    scFilm_v_Var.get())
                labelImageEffectVar.set(image_effect_setting + " " + str(film_para))
                camera.image_effect_params = film_para
            elif image_effect_setting == 'watercolor':
                if cbWatercolor_uv_Var.get():
                    watercolor_para = (
                        scWatercolor_u_Var.get(),
                        scWatercolor_v_Var.get())
                    labelImageEffectVar.set(image_effect_setting + " " + str(watercolor_para))
                    camera.image_effect_params = watercolor_para
                else:
                    watercolor_para = ()
                    labelImageEffectVar.set(image_effect_setting + " " + str(watercolor_para))
                    camera.image_effect_params = watercolor_para

        if rqs == RQS_CAPTURE:
            print("Capture")
            rqs=RQS_0
            timeStamp = time.strftime("%Y%m%d-%H%M%S")
            jpgFile='img_'+timeStamp+'.jpg'
            camera.resolution = (2592, 1944)    #set photo size
            camera.capture(jpgFile)
            camera.resolution = (400, 300)      #resume preview size
            labelCapVal.set(jpgFile)
        else:
            stream = io.BytesIO()
            camera.capture(stream, format='jpeg')
            stream.seek(0)
            tmpImage = Image.open(stream)
            tmpImg = ImageTk.PhotoImage(tmpImage)
            previewPanel.configure(image = tmpImg)
            #sleep(0.5)
                
    print("Quit")        
    #camera.stop_preview()
    
def startCamHandler():
    camThread = Thread(target=camHandler)
    camThread.start()

def quit():
    global rqs
    rqs=RQS_QUIT

    global tkTop
    tkTop.destroy()

def capture():
    global rqs
    rqs = RQS_CAPTURE
    labelCapVal.set("capturing")

def cbScaleSetting(new_value):
    global rqsUpdateSetting
    rqsUpdateSetting = True

def cbButtons():
    global rqsUpdateSetting
    rqsUpdateSetting = True

tkTop = tk.Tk()
tkTop.wm_title("helloraspberrypi.blogspot.com")
tkTop.geometry('1000x650')

previewWin = tk.Toplevel(tkTop)
previewWin.title('Preview')
previewWin.geometry('400x300')
previewPanel = tk.Label(previewWin)
previewPanel.pack(side = "bottom", fill = "both", expand = "yes")

#tkButtonQuit = tk.Button(tkTop, text="Quit", command=quit).pack()

tkButtonCapture = tk.Button(
    tkTop, text="Capture", command=capture)
tkButtonCapture.pack()

SCALE_WIDTH = 980;

labelCapVal = tk.StringVar()
tk.Label(tkTop, textvariable=labelCapVal).pack()

notebook = ttk.Notebook(tkTop)
frame1 = ttk.Frame(notebook)
frame2 = ttk.Frame(notebook)
frame3 = ttk.Frame(notebook)
notebook.add(frame1, text='Setting')
notebook.add(frame2, text='White Balance')
notebook.add(frame3, text='Image Effect')
notebook.pack()

# Tab Setting
scaleSharpness = tk.Scale(
    frame1,
    from_=-100, to=100,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="sharpness",
    command=cbScaleSetting)
scaleSharpness.set(0)
scaleSharpness.pack(anchor=tk.CENTER)

scaleContrast = tk.Scale(
    frame1,
    from_=-100, to=100,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="contrast",
    command=cbScaleSetting)
scaleContrast.set(0)
scaleContrast.pack(anchor=tk.CENTER)

scaleBrightness = tk.Scale(
    frame1,
    from_=0, to=100,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="brightness",
    command=cbScaleSetting)
scaleBrightness.set(50)
scaleBrightness.pack(anchor=tk.CENTER)

scaleSaturation = tk.Scale(
    frame1,
    from_=-100, to=100,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="saturation",
    command=cbScaleSetting)
scaleSaturation.set(0)
scaleSaturation.pack(anchor=tk.CENTER)

scaleExpCompensation = tk.Scale(
    frame1,
    from_=-25, to=25,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="exposure_compensation",
    command=cbScaleSetting)
scaleExpCompensation.set(0)
scaleExpCompensation.pack(anchor=tk.CENTER)

# Tab White Balance

lfAwbMode = ttk.LabelFrame(frame2, text="awb_mode")
lfAwbMode.pack(fill="x")
lfAwbGains = ttk.LabelFrame(frame2, text="awb_gains")
lfAwbGains.pack(fill="x")

labelAwbVar = tk.StringVar()
tk.Label(lfAwbMode, textvariable=labelAwbVar).pack()

#--
AWB_MODES = [
    ("off", "off"),
    ("auto", "auto"),
    ("sunlight", "sunlight"),
    ("cloudy", "cloudy"),
    ("shade", "shade"),
    ("tungsten", "tungsten"),
    ("fluorescent", "fluorescent"),
    ("incandescent", "incandescent"),
    ("flash", "flash"),
    ("horizon", "horizon"),
    ]

varAwbMode = tk.StringVar()
varAwbMode.set("auto")
for text, awbmode in AWB_MODES:
    awbModeBtns = tk.Radiobutton(
        lfAwbMode,
        text=text,
        variable=varAwbMode,
        value=awbmode,
        command=cbButtons)
    awbModeBtns.pack(anchor=tk.W)
#--
scaleGainRed = tk.Scale(
    lfAwbGains,
    from_=0.0, to=8.0,
    resolution=0.1,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="Red",
    command=cbScaleSetting)
scaleGainRed.set(0.0)
scaleGainRed.pack(anchor=tk.CENTER)

scaleGainBlue = tk.Scale(
    lfAwbGains,
    from_=0.0, to=8.0,
    resolution=0.1,
    length=SCALE_WIDTH,
    orient=tk.HORIZONTAL,
    label="Blue",
    command=cbScaleSetting)
scaleGainBlue.set(0.0)
scaleGainBlue.pack(anchor=tk.CENTER)

# Tab Image Effect
#For Image effects, ref:
#http://picamera.readthedocs.org/en/latest/api_camera.html?highlight=effect#picamera.camera.PiCamera.image_effect
labelImageEffectVar = tk.StringVar()
tk.Label(frame3, textvariable=labelImageEffectVar).pack()
#-- image_effect

varImageEffect = tk.StringVar()
varImageEffect.set('none')

lfNoParaOpts1 = ttk.Frame(frame3)
lfNoParaOpts1.pack(fill="x", expand="yes")

tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='none',value='none',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='negative',value='negative',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='sketch',value='sketch',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='denoise',value='denoise',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='emboss',value='emboss',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='oilpaint',value='oilpaint',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='hatch',value='hatch',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts1, variable=varImageEffect,
        text='gpen',value='gpen',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

lfNoParaOpts2 = ttk.Frame(frame3)
lfNoParaOpts2.pack(fill="x", expand="yes")
tk.Radiobutton(lfNoParaOpts2, variable=varImageEffect,
        text='pastel',value='pastel',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts2, variable=varImageEffect,
        text='saturation',value='saturation',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts2, variable=varImageEffect,
        text='washedout',value='washedout',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts2, variable=varImageEffect,
        text='cartoon',value='cartoon',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts2, variable=varImageEffect,
        text='deinterlace1',value='deinterlace1',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfNoParaOpts2, variable=varImageEffect,
        text='deinterlace2',value='deinterlace2',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

lfSolarize = ttk.LabelFrame(frame3, text="solarize")
lfSolarize.pack(fill="x", expand="yes")

tk.Radiobutton(lfSolarize, variable=varImageEffect,
        text='solarize',value='solarize',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

cbSolarize_yuv_Var = tk.BooleanVar()
tk.Checkbutton(lfSolarize, text="yuv",
    variable=cbSolarize_yuv_Var, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

scSolarize_x0_Var = tk.IntVar()
scSolarize_x0_Var.set(128)
tk.Scale(lfSolarize, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="x0",
    variable=scSolarize_x0_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scSolarize_y0_Var = tk.IntVar()
scSolarize_y0_Var.set(128)
tk.Scale(lfSolarize, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="y0",
    variable=scSolarize_y0_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scSolarize_y1_Var = tk.IntVar()
scSolarize_y1_Var.set(128)
tk.Scale(lfSolarize, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="y1",
    variable=scSolarize_y1_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scSolarize_y2_Var = tk.IntVar()
scSolarize_y2_Var.set(0)
tk.Scale(lfSolarize, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="y2",
    variable=scSolarize_y2_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

lfwatercolor = ttk.LabelFrame(frame3, text="watercolor")
lfwatercolor.pack(fill="x", expand="yes")
tk.Radiobutton(lfwatercolor, variable=varImageEffect,
        text='watercolor',value='watercolor',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

cbWatercolor_uv_Var = tk.BooleanVar()
cbWatercolor_uv_Var.set(False)
tk.Checkbutton(lfwatercolor, text="uv",
    variable=cbWatercolor_uv_Var, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

scWatercolor_u_Var = tk.IntVar()
scWatercolor_u_Var.set(0)
tk.Scale(lfwatercolor, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="u",
    variable=scWatercolor_u_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)
scWatercolor_v_Var = tk.IntVar()
scWatercolor_v_Var.set(0)
tk.Scale(lfwatercolor, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="v",
    variable=scWatercolor_v_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

lffilm = ttk.LabelFrame(frame3, text="film")
lffilm.pack(fill="x", expand="yes")
tk.Radiobutton(lffilm, variable=varImageEffect,
        text='film',value='film',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

scFilm_strength_Var = tk.IntVar()
scFilm_strength_Var.set(0)
tk.Scale(lffilm, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="strength",
    variable=scFilm_strength_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)
scFilm_u_Var = tk.IntVar()
scFilm_u_Var.set(0)
tk.Scale(lffilm, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="u",
    variable=scFilm_u_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)
scFilm_v_Var = tk.IntVar()
scFilm_v_Var.set(0)
tk.Scale(lffilm, from_=0, to=255,
    orient=tk.HORIZONTAL, length=200, label="v",
    variable=scFilm_v_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

lfblur = ttk.LabelFrame(frame3, text="blur")
lfblur.pack(fill="x", expand="yes")
tk.Radiobutton(lfblur, variable=varImageEffect,
        text='blur',value='blur',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
scBlur_size_Var = tk.IntVar()
scBlur_size_Var.set(1)
tk.Scale(lfblur, from_=1, to=2,
    orient=tk.HORIZONTAL, length=100, label="size",
    variable=scBlur_size_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

lfcolorswap = ttk.LabelFrame(frame3, text="colorswap")
lfcolorswap.pack(fill="x", expand="yes")
tk.Radiobutton(lfcolorswap, variable=varImageEffect,
        text='colorswap',value='colorswap',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
cbColorswap_dir_Var = tk.BooleanVar()
cbColorswap_dir_Var.set(False)
tk.Checkbutton(lfcolorswap, text="dir - 0:RGB to BGR/1:RGB to BRG",
    variable=cbColorswap_dir_Var, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

lfposterise = ttk.LabelFrame(frame3, text="posterise")
lfposterise.pack(fill="x", expand="yes")
tk.Radiobutton(lfposterise, variable=varImageEffect,
        text='posterise',value='posterise',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
scPosterise_steps_Var = tk.IntVar()
scPosterise_steps_Var.set(4)
tk.Scale(lfposterise, from_=2, to=32,
    orient=tk.HORIZONTAL, length=200, label="steps",
    variable=scPosterise_steps_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

lfcolorpoint = ttk.LabelFrame(frame3, text="colorpoint")
lfcolorpoint.pack(fill="x", expand="yes")
tk.Radiobutton(lfcolorpoint, variable=varImageEffect,
        text='colorpoint',value='colorpoint',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
quadrantVar = tk.IntVar()
quadrantVar.set(0)
tk.Radiobutton(lfcolorpoint, text="green",
    variable=quadrantVar, value=0, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfcolorpoint, text="red/yellow",
    variable=quadrantVar, value=1, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfcolorpoint, text="blue",
    variable=quadrantVar, value=2, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)
tk.Radiobutton(lfcolorpoint, text="purple",
    variable=quadrantVar, value=3, command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

lfcolorbalance = ttk.LabelFrame(frame3, text="colorbalance: I can't see the effect!")
lfcolorbalance.pack(fill="x", expand="yes")
tk.Radiobutton(lfcolorbalance, variable=varImageEffect,
        text='colorbalance',value='colorbalance',command=cbButtons).pack(anchor=tk.W, side=tk.LEFT)

scColorbalance_lens_Var = tk.DoubleVar()
scColorbalance_lens_Var.set(0)
tk.Scale(lfcolorbalance, from_=0, to=256,
    orient=tk.HORIZONTAL, length=140, label="lens",
    variable=scColorbalance_lens_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scColorbalance_r_Var = tk.DoubleVar()
scColorbalance_r_Var.set(1)
tk.Scale(lfcolorbalance, from_=0, to=256,
    orient=tk.HORIZONTAL, length=140, label="r",
    variable=scColorbalance_r_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scColorbalance_g_Var = tk.DoubleVar()
scColorbalance_g_Var.set(1)
tk.Scale(lfcolorbalance, from_=0, to=256,
    orient=tk.HORIZONTAL, length=140, label="g",
    variable=scColorbalance_g_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scColorbalance_b_Var = tk.DoubleVar()
scColorbalance_b_Var.set(1)
tk.Scale(lfcolorbalance, from_=0, to=256,
    orient=tk.HORIZONTAL, length=140, label="b",
    variable=scColorbalance_b_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scColorbalance_u_Var = tk.IntVar()
scColorbalance_u_Var.set(0)
tk.Scale(lfcolorbalance, from_=0, to=255,
    orient=tk.HORIZONTAL, length=140, label="u",
    variable=scColorbalance_u_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

scColorbalance_v_Var = tk.IntVar()
scColorbalance_v_Var.set(0)
tk.Scale(lfcolorbalance, from_=0, to=255,
    orient=tk.HORIZONTAL, length=140, label="v",
    variable=scColorbalance_v_Var, command=cbScaleSetting).pack(anchor=tk.W, side=tk.LEFT)

#=======================================
print("start")
startCamHandler()

tk.mainloop()

---

updated@2016-04-15:
Current Raspbian Jessie come with PIL installed by default, but no ImageTk. If you run Python script reported with error:
ImportError: cannot import name ImageTk

Install python-imaging-tk
$ sudo apt-get install python-imaging-tk

---

Updated@2021-03-09:

~ Another version with preview on local HMDI display.