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Background Blurring. [email protected] Outline. Introduction Documentation Object Segmentation Depth Map Generation Image Defocus. Perspective Box. Lazy Snapping. Camera Settings. Pop-up Card. Defocus Blur. Privacy Preserving. Photo Browser. Method. Depth Map Generation.

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Background blurring

Background Blurring

[email protected]


Outline

Outline

  • Introduction

  • Documentation

    • Object Segmentation

    • Depth Map Generation

    • Image Defocus


Method

Perspective Box

Lazy Snapping

Camera Settings

Pop-up Card

Defocus Blur

Privacy Preserving

Photo Browser

Method

Depth Map Generation

Perspective Box

Object Segmentation

Pop-up Card

Applications

Lazy Snapping

Image Defocus

Camera Settings


Method1

Method

User Stroke

Resize to 20%

  • Segment

    • Lazy snapping

    • Mean shift

Mean shift

Do hard graph cut by lazy snapping

Lazy Snapping. ACM Trans. On Graphics 2004.

Mean Shift: A Robust Approach Toward Feature Space Analysis. PAMI 2002.

A Bayesian Approach to Digital Matting. CVPR 2001.


Method2

Method

Perspective Box

Pop-up card

Pop-up card

  • Depth map

    • Perspective Box

      • Vanish point

      • Rear wall

Normal vector

Normal vector

Depth Map

Depth Map

Tour Into the Picture: Using a spidery mesh user interface to make animation from a single image. SIGGRAPH 1997


Method3

Method

Perspective Box

Pop-up card

Pop-up card

  • Depth map

    • Pop-up card

Normal vector

Normal vector

Depth Map

Depth Map


Method4

Method

Perspective Box

Pop-up card

  • Depth map

    • Normal vector

Normal vector

Normal vector

Depth Map

Depth Map


Method5

Method

  • Defocus blur

    • bokeh

x


Method6

Method

  • Defocus blur


Method7

Method

  • Near-by object case

Focus on the flower

Focus on the flower


Method8

Method

Blur circle diameter

Objects in front of the focus

Objects behind

the focus

  • Near-by object case

Blur shape as alpha map

Texture synthesis inpainting

Defocus Blur

Defocus Blur

Interpolation by alpha map

Shallow focus image


Experimental result 1

Experimental Result 1

  • Defocus blur method proposed in the system comparing with other blur filter results

Deep focus

Shallow focus


Experimental result 11

Experimental Result 1

  • Defocus blur method proposed in the system comparing with other blur filter results

Gaussian blur

Defocus blur

Defocus blur + Bokeh


Experimental result 12

Experimental Result 1

Deep focus

Shallow focus


Experimental result 13

Experimental Result 1

Original photograph

  • Defocus blur method proposed in the system comparing with other blur filter results

Gaussian blur

Defocus blur

Defocus blur + Bokeh


Experimental result 2

Experimental Result 2

  • Near-by object case

Focus on the flower

Focus on the flower


Experimental result 21

Experimental Result 2

  • Near-by object case

Interpolation result

Without inpainting


Applications privacy preserving

Applications - Privacy Preserving


Applications image transition at photo browser

Applications - Image Transition at Photo Browser


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Applications - Image Transition at Photo Browser


Applications image transition at photo browser1

Applications - Image Transition at Photo Browser

Movie with defocus blur effect


Documentation

Documentation


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  • ./ 系統主要分成三部份,前兩塊產生出depth和segment的資訊之後,可以在第三部份根據不同參數設定產生出不同的效果

    • system

      • 1_segmentation

        • Tool1: lazy-snapping with simple UI

        • Tool2: 光影魔術手

      • 2_depthmap

        • depth of background scene (3d-box)

        • depth of each segment

      • 3_refocusblur

        • camera parameter

        • refocusing (inpainting, defocus blur)

    • sample// sample input, parameter and result


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  • Segmentation

    • Lazy snapping

      • Tool1: preprocessing(resize for mean shift ) + lazy snapping

      • Lzsegment.m

        • Input : parameter file name

          先做preprocessing,這裡可以用meanshift或是直接downsample成64色階,並且在meanshift的地方resize為五分之一加快速度,

          讀取stroke_1.bmp, stroke_2.bmp…等前後景筆劃圖,前景是紅色,後景是藍色。然後執行lazy snapping處理

          ◎每個segment都存一個灰階的bmp檔,檔名分別是seg_1.bmp, seg_2.bmp…沒有先後順序。將每個segment扣除剩下的background的部份,即是seg_segN.bmp

          ◎需要libgil2的library

      • Tool2:光影魔術手

      • 每個segment都存一個png檔,檔名分別是obj_1.png, obj_2.png…將這些png檔的alpha值轉成bmp, 並且扣除只剩下background的部份,即是seg_segN.bmp


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  • Depth map

    • depth.m(function depth(parafilename))

      • Input:

        • parameter file name

        • dep_1.dat, dep_2.dat, …dep_(segN-1).dat

          ★ 每個dep_n.dat的內容:

          nxny

          p1x p1y

          p2x p2y

          ★ n表示normal vector, 預設是 (0,0), vector方向代表物體在平面上的法向量方向,長度表示深度變化量

          ★ p1,p2…是user劃下的筆劃座標,即此segment的深度參考點,預設是segment最下方的點。如果沒有p1,p2…系統會自動取segment最下方一列的點作為參考點。

      • Output:

        • dep_1.bmp, dep_2.bmp … dep_segN.bmp


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  • Refocus Blur

    • refocus.m

      ( function [finalresult]=defocus(parafilename) )

      • Get parameter from file, and load the segment/depth bmp files

      • Get the focus position from focusposition.dat

      • Compute diffusion blur circle diameter for each pixel

      • Devide image into two parts, the part in front of the focus, and run defocus_blur.m

      • Use alpha.m to get alpha map, and find the pixels to run inpaint.m

      • Use the result by inpaint.mto call defocus_blur.m

      • Combine the front part and back part by alpha map

      • return the result image


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  • others

    • Inpainting function needs the estexemplarhelper.c

      run mexestexemplarhelper.cbefore the function call at first time

      The inpainting code (inpaint.m) is from http://www.cc.gatech.edu/~sooraj/inpainting/

    • Meanshift code is downloaded from

    • http://www.caip.rutgers.edu/riul/


Input parameter file

Input parameter file

  • 1.dirnamediratory of the files, include '/' on the tail, ex: 'sample1/'

  • 2.imagenamefile name of input image, ex: test.jpg

  • 3.segNnumber of segment image, include the background.

    ex: 2 (foreground*1+background)

  • 4.vx position of vanish point, must be in the rear wall,

  • 5.vybut can be outside of the image

  • 6.ax

  • 7.ayleft_top position of the rear wall

  • 8.bx

  • 9.byright_bottom position of the rear wall

  • 10.dc_flens focal length,(mm) ex: 50 mm, 100 mm ...etc.

  • 11.dpmaxthe depth of pixels with color level 255 in depth map, (mm)

  • 12.dnearthe depth of pixels with color level 0 in depth map, (mm)

  • 13.dc_Nthe aperture number

  • 14.thr=250threshold of bokeh color level

  • 15.light_e=0.5little constant number for light_weight function

  • 16.lens shape default setting 0 is flat disk


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  • Camera parameter

  • dc_f相機的焦距,單位是mm,數值越大景深越淺,

    建議在50~100之間

  • Dpmaxrear wall距離成像平面的距離,建議為5~50公尺 (5000~50000)

  • Dnear場景裡距離成像平面最近的物體距離,

    建議為1公尺,至少要在兩倍焦距以上

  • dc_N光圈值,數值越大,光圈孔隙越小,景深越深,

    為達到淺景深效果建議值在1.4~2.8之間,越小效果越強

  • thr=250將pixel產生散景效果的臨界值,建議不要低於240

  • light_e=0.5weight function的明度微調參數,為一個大於0的值,

    數值越大明度影響越低,建議為0.5~1之間

  • lens shape 光圈孔隙的形狀,預設為0

    對應到refocus/lens/ 資料夾底下的0.bmp, 1.bmp


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  • Sample

    • ./

      • parameter01-.dat

    • ./sample01

      • original image

      • seg_1.bmp seg_2.bmp …

      • dep_1.dat dep_2.dat …

        • 可由UI產生

      • focusposition.dat

        • 可由UI產生,給定要聚焦的點,可以為單一或是多個點,將會取其對應到的深度平均值,格式為

          x1 y1

          x2 y2

      • dep_1.bmp dep_2.bmp …


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  • 執行:

    • 用system的前兩步驟產生出前頁所述的參數和bmp files,並放在所屬資料夾下

    • result = refocus(parameter file name);


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END

THANK YOU


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