was this done with Kang et al's code from http://www.columbia.edu/~ph2360/COMS6734/FinalProject/ ?
It works slightly better on faces if you only process the red channel rather than first mixing the input image down to black and white.
(and the images are easier to evaluate in positive form. Scratchboard art isn't meant to be a negative image, it's just that you draw by removing black. with this code as it stands it's not suitable for scratchboard work because it would be a mostly-white result with just a few lines left in black that were not scratched away. What we need is a variation of this that draws in white lines on black but not by scraping away large areas *or* drawing lines that look like a negative image.
one good side effect of using the ETF for cutting away large white areas is that the cut tracks look hand drawn as opposed to most of the engraving fill techniques (scanlines or polygon insetting) which look obviosly machine draw. (of course this only aplies when cutting real scratchboard from one of these images rather than on a computer display where white is just white with no texture...)
For the face quality, it depends on the choices of the parameters and also depends on the image content. You may be right sometimes the single channel works better.
Yes, the ETF edges cannot represent the scratchboard style. It's only a type of edge detection but with good stylization. Scratchboard might have some lines to indicate tone or the highlighted areas.
was this done with Kang et al's code from http://www.columbia.edu/~ph2360/COMS6734/FinalProject/ ?
ReplyDeleteIt works slightly better on faces if you only process the red channel rather than first mixing the input image down to black and white.
(and the images are easier to evaluate in positive form. Scratchboard art isn't meant to be a negative image, it's just that you draw by removing black. with this code as it stands it's not suitable for scratchboard work because it would be a mostly-white result with just a few lines left in black that were not scratched away. What we need is a variation of this that draws in white lines on black but not by scraping away large areas *or* drawing lines that look like a negative image.
one good side effect of using the ETF for cutting away large white areas is that the cut tracks look hand drawn as opposed to most of the engraving fill techniques (scanlines or polygon insetting) which look obviosly machine draw. (of course this only aplies when cutting real scratchboard from one of these images rather than on a computer display where white is just white with no texture...)
regards
Graham
Yes, it is from one of Kang's paper.
ReplyDeleteFor the face quality, it depends on the choices of the parameters and also depends on the image content. You may be right sometimes the single channel works better.
Yes, the ETF edges cannot represent the scratchboard style. It's only a type of edge detection but with good stylization. Scratchboard might have some lines to indicate tone or the highlighted areas.