UNIZA@Mediaeval 2014 Visual Privacy Task: Object

Transparency Approach

Martin Paralič, Roman Jarina, (martin.paralic, roman.jarina)@fel.uniza.sk

presented by Tomáš Piatrik

Proposed FilterORIGINAL

VIDEO

XMLMETADATA

PRE-COMPUTEDBACKGROUND

(TIME-MEDIAN)

FACEBBOX

MASK(ELLIPTIC SHAPE) FILTERED

VIDEO

MASKING BY BACKGROUND

Background estimation

…

RGB(x,y)

video stream

Sequence of RGBvalues for each pixel

in the time.(Black pixels are excluded.)

Masking foreground objectsby black pixels. Background image computed

as time median of each pixel.

Some pixels has no sequence (black). Foreground pixel has penetrated the sequence (when missing background pixels).

Sufficient sequences to estimate the background.

Advandages / disatvantages

Advantages• Easy to implement.• Low computation cost

of filtering stream.• Only minimal

distortion of the original image.

Disatvantages• High computation cost of

the background image estimation.

• For the long standing foreground objects must be used masking.

• Some background pixels are never visible. In this case the foreground pixels may penetrate in to the sequence.