Geoff’s photo doodler – Advanced Menu

As I add functionality to the program I have started a second menu to provide more space to place the controls. When you have loaded the image to draw, you can activate the Advanced menu by pressing the A key. If the advanced menu is showing, pressing A will hide it.

The algorithm used for movement of the “pen” as it draws, is to select a number of possible destinations at Line step length from the current point in the general direction the pen is currently moving (adjusted by the Samples selecting direction and Direction Range parameters). To allow more flexibility, you can substitute a different image to provide the brightness levels for this algorithm. Here are some examples: first with the default original image; second with a plain gray image; third with an edit of the original image that emphasises some of the edges and textures.

By default, the original image is used as the mask image to guide the pen movement (selecting the next point as the closest match to brightness of the current point). You can see here that lines tend to align with textures in the feathers, for example.
Using a featureless mask image means the pen movements will not be guided by structures in the original image. The line paths are more random and do not pick up paths from the underlying image.
Using a custom mask might provide regions that “capture” the pens or cause the pens to follow particular lines. Here I have made a mask by using a find-edge filter, blurring this slightly, and painting out the detail in the bill. The drawn lines tend to align with structures in the mask image.

The Mouse Attractiveness setting in line drawing modep allows you to direct where the pens move. If you set a high value for this parameter and then click on the drawing as it develops, the pens will be drawn towards the mouse cursor location. You can use this to dynamically increase the density of drawn lines to different parts of the image.

Auto adjust circle size works in circle drawing mode. This will reduce the size of circles drawn on the image depending on the amount of detail in the area around the circle centre.

Note the variation in circle size with the Auto adjust circle size control selected. Areas without fine detail such as the background at top right get larger circles that areas with fine detail such as the eyes.

Another way to focus line drawing is to apply a Pen initiator mask. This is an image where brighter areas will preferentially get pens starting when you reset a drawing. Black areas on the pen initiator mask image will get few or no pens, though the pens may wander into those areas as the drawing develops.

The Pen initiator mask allows you some control over where the pens start drawing the lines. Here the pen initiator mask image is a black canvas with a white area centred on the middle of the image where the cat is positioned in the source image. Line drawing is dense over the cat, but a few lines have wandered from their starting position to meander over the background to give some hints of the detail there.

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