Traditional gradient domain seamless image cloning is a time consuming task

requiring the solving of Poisson’s equations whenever the shape or position of the cloned region changes. Recently

a more efficient alternative

the mean-value coordinates (MVCs) based approach

was proposed to interpolate interior pixels by a weighted combination of values along the boundary. However

this approach cannot faithfully preserve the gradient in the cloning region. In this paper

we introduce harmonic cloning

which uses harmonic coordinates (HCs) instead of MVCs in image cloning. Benefiting from the non-negativity and interior locality of HCs

our interpolation generates a more accurate harmonic field across the cloned region

to preserve the results with as high a quality as with Poisson cloning. Furthermore

with optimizations and implementation on a graphic processing unit (GPU)

we demonstrate that

compared with the method using MVCs

our harmonic cloning gains better quality while retaining real-time performance.