- Tong - on wrote... | Hi Anthony, | | On http://www.imagemagick.org/Usage/photos/, in Photo Conversion | Cookbook section you have two examples on converting photos to | sketches -- "Childrens Color-In Images" & "Pencil Sketch". | | Before going into these, maybe it is a good idea to first discuss | convert's built-in -charcoal operator, just to make it a full | story, because there might be people who don't know of the operator. |
I'll add a link to my own discussion... http://www.imagemagick.org/Usage/transform/#charcoal :-) But the two methods you mention are not really using charcoal as such. In that case it is used more as a edge detection method, to generate disgonal pencil lines. I have added a new 'photo transform' for charcoal. http://www.imagemagick.org/Usage/photos/#charcoal Give it a day to so for it to appear on the main IM exmaple site. | Moreover, when I apply the Childrens Color-In Image method to a | portrait photo, it did not work well. I know that the Childrens | Color-In Image method was originated from a long discussion about | Generating Coloring-In Pages on the IM Users Forum. So I'm | thinking, let's try another algorithm. | Good, because I am certainly not happy with it! | What I really like to see in the Photo Conversion Cookbook | section, is an example for "Simplest Sketch", ie, convert the | photo to a sketch that has bare minimum lines to represent the | original photo. I found a very good algorithm from the gimp | tutorials section. | | http://www.gimp.org/tutorials/Sketch_Effect/ | No that is a great effect!!! In fact such an effect of removing unimportant lines may be a good one for image comparision too! | To be honest, I was just stunned by how good the effect can be. | I had been trying to achieve the same result in gimp long time ago | using my limited understanding/knowledge but failed. Looking at | how a machine can do in just several simples steps, I have to say I | was amazed. I think that's a very effective algorithm, but I don't | know how to do it in IM. | Hmmm highpass fiter: -- not sure... Anyone? blur: -blur 0x7 invert -negate we need the original then do a opacity 50% and add.. Command so far... convert image.png \( +clone -median 2 -blur 0x7 -negate \) \ -matte -channel A -evaluate set 50% -compose plus -composite \ ... Hmmm our image has some color in it but it is close. prehaps I have the point of cloning wrong, or I have the high pass filter wrong (likely) Continuing increase contrast -sigmoidal-contrast 7x50% or -normalize prehaps with a controled 'denormalize' or greying... http://www.imagemagick.org/Usage/color/#greying After that is simular to using various stech and edge detection. Of course some manual (sic) handling was also done. Anyone like to improve this? ------------------------- Another technique I would like to see converted to IM is.... Watercolors from photos... http://www.state-of-entropy.com/watercolor.html Though the title image is great looking, the example image used is not so good. Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]> ----------------------------------------------------------------------------- "I have a top secret gravely important assignment here." "What other kind do I ever get?" -- Stainless Steel Rat (Revenge) ----------------------------------------------------------------------------- Anthony's Home is his Castle http://www.cit.gu.edu.au/~anthony/ _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
