1) How can I expand and contract "selection" (PS menu Selection/Modify/Expand or Contract) ... I mean I would like to select routes and streets from image (light white or light gray) and fill them with white color; the rest is black. So I would like to extend the white +3 and contract it back -3.
2) Does IM has some algorithm to detect amount of pixels in a group of pixels? PS has function magic wend, so when you click pixel of some color, all nearby pixels are selected. And I need to detect amount of these pixels because I would like to remove the pixels (fill them black) if the amount is less than eg. 150. In my case the image is B/W.
3) Then I want to make relief (is it right word?) to get only the edges of the selection. Therefor I look for filter function like in PS - its called "Glowing edges" under Filter/Style menu.
4) Next thing, I would like to generate grid, where I would define color, count of lines and width if lines.
5) can you help me to simulate a light of streetlight shining in the night? For example if I would darken daylight image of aerial photo, I would like to place a streetlight there. I know I can use blending, but would need some idea how to create a cycle, with a gradient mask (also cycle) that will go to outwards (white inside, black outside).
I have idea. When I have the selection of the streets and routes (white mask on black background) I could spread the white pixels out. Something like blur function but only for white color ant lighten effect would be used. So this way I would generate light mask. Then I need dark background (almost black) for the places where is not any light. Then I need new layer with dark image of the town and I need to convert it to orange tones. Like the light of night city:
http://upload.wikimedia.org/wikipedia/c ... 007%29.jpg
So now I would just connected the mask to get similar effect like in the link.
So my questions here:
A) how to spread the white pixels
B) how to generate the orange light over the dark image. I think I should darken the image with -level and then create new layer with the original photo and change the channel settings. And overlay.