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Re: Thanks and a question/suggestion

From: Tony Cook (
Date: Sun 10 Nov 2002 - 22:52:00 GMT

  • Next message: Tony Cook: "Re: Thanks and a question/suggestion"

    On Sun, Nov 10, 2002 at 07:58:05AM +0100, Georg Rehfeld wrote:
    > You all know, what photoshop/gimp can do with brushes: draw
    > points, lines, polylines using a little image, typically more
    > opaque in the center and transparent in the outer regions. The brush
    > is grayscale with transparency. The essential point is: along a
    > line the brush image is not stupidly used pixel for pixel to
    > overdraw, what is in the image already, as with GD. Instead the
    > outer regions along the line have the brush transparency preserved
    > so that a nice antialiased line is drawn over the image.

    I have looked at this, but work and other interests have kept me busy
    for a while.

    > Remember, I'm NOT an expert at all, but I believe, one way to go
    > is:
    > - have a temporary grayscale buffer for the line to draw,
    > initialized to all transparent
    > - draw the brush pixels only there, where the buffer is more
    > transparent or more light
    > - copy the buffer onto the image with transparency (rubthrough)
    > and in the requested foreground color

    This is the mechanism I'd been planning on using for greyscale brushes,
    though I'm not sure it would work for colour brushes. I'd also planned
    on having the ability to apply a texture to the brush.

    Unfortunately work and other interests have kept me away from Imager for
    a while.

    Tony Cook