draw_bezier

draw_bezier (FloatPoint start, FloatPoint c1, FloatPoint c2, FloatPoint end, Pixel value, float accuracy = 0.10)

Draws a cubic bezier curve

Coordinates are absolute and not relative to the offset of the image. Therefore, if the image offset is (5, 5), a curve at (5, 5) will be in the upper left hand corner of the image.

start:

The start FloatPoint.

c1:

The control point associated with the start point.

c2

The control point associated with the end point.

end

The end FloatPoint.

value:

The pixel value to set for the curve.

accuracy = 0.1:

The rendering accuracy (in pixels)

Example 1: draw_bezier

draw_circle

draw_circle (FloatPoint c, float r, Pixel value, float thickness, float accuracy)

Draws a center centered at c with radius r.

Coordinates are absolute and not relative to the offset of the image. Therefore, if the image offset is (5, 5), a line at (5, 5) will be in the upper left hand corner of the image.

c:

The center of the circle

r:

The radius of the circle

value:

The pixel value to set for the line.

thickness = 1.0:

The thickness of the circle (in pixels)

accuracy = 0.1:

The accuracy of the circle drawing

Based on the "approximating a circle with Bezier curves" approach. http://www.whizkidtech.redprince.net/bezier/circle/

Example 1: draw_circle

draw_filled_rect

draw_filled_rect (FloatPoint ul, FloatPoint lr, Pixel value)

Draws a filled rectangle.

Coordinates are absolute and not relative to the offset of the image. Therefore, if the image offset is (5, 5), a rectangle at (5, 5) will be in the upper left hand corner of the image.

The coordinates can be specified either by four integers, two FloatPoints, or one Rect:

draw_filled_rect (FloatPoint(x1, y1), FloatPoint(x2, y2), value)

draw_filled_rect (Rect rect, value)

Example 1: draw_filled_rect

draw_hollow_rect

draw_hollow_rect (FloatPoint ul, FloatPoint lr, Pixel value, float thickness)

Draws a hollow rectangle.

Coordinates are absolute and not relative to the offset of the image. Therefore, if the image offset is (5, 5), a rectangle at (5, 5) will be in the upper left hand corner of the image.

The coordinates can be specified either by two FloatPoints or one Rect:

draw_hollow_rect (FloatPoint(x1, y1), FloatPoint(x2, y2), value, thickness = 1.0)

draw_hollow_rect (Rect rect, value, thickness = 1.0)

value:

The pixel value to set for the lines.

thickness = 1.0:

The thickness of the outline

Example 1: draw_hollow_rect

draw_line

draw_line (FloatPoint start, FloatPoint end, Pixel value, float thickness)

Draws a straight line between two points.

Coordinates are absolute and not relative to the offset of the image. Therefore, if the image offset is (5, 5), a line at (5, 5) will be in the upper left hand corner of the image.

a:

The start FloatPoint.

b:

The end FloatPoint.

value:

The pixel value to set for the line.

thickness = 1.0:

The thickness of the line (in pixels)

The implementation is based on the classic Bresenham algorithm, as described in J. E. Bresenham: Algorithm for computer control of a digital plotter. IBM Systems Journal 4, pp. 25-30 (1965).

Example 1: draw_line

draw_marker

draw_marker (FloatPoint location, int size = 5, Choice [+|x|hollow_square|filled_square] style = +, Pixel value)

Draws a marker at a given point.

Coordinates are absolute and not relative to the offset of the image. Therefore, if the image offset is (5, 5), a marker at (5, 5) will be in the upper left hand corner of the image.

a

The position of the marker.

size

The size of the marker (number of pixels)

style

PLUS + (0)

X + (1)

HOLLOW_SQUARE (2)

FILLED_SQUARE (3)

value

The pixel value to set for the line.

Example 1: draw_marker

draw_text

draw_text (FloatPoint p, str text, Pixel color, int(3, 512) size = 10, Choice [serif|sans-serif|monospace] font_family, bool italic = False, bool bold = False, Choice [left|center|right] halign)

Draws text onto the image. The results are fairly primitive. The text is not anti-aliased, but should be adequate for marking up the image for debugging purposes.

This function relies on wxPython for font rendering. Therefore, wxPython must be installed, and it must be runnable in the current environment, for example, a connection to a display or X server must be available. This may not be the case when running over a remote terminal, for example.

p

The position of the text. The x component will be either at the left, center, or right of the text, depending on the value of halign. The y component specifies the top of the text.

text

The string to be drawn on the image. If this is an 8-bit string the string should be encoded in the default encoding for your system. If a Unicode string, the text will be rendered using a Unicode font. This requires that your wxPython version is compiled with Unicode support.

color

The color of the text to be drawn. Note that there are some peculiarities for ONEBIT images:

If color is zero, the text will be white. If non-zero, the text will be black. It is not possible to set different values for the text.

family

The font family to be used. For platform independence, this argument takes a general typeface style which will be mapped to an appropriate typeface on each platform.

SERIF (0)

SANS-SERIF (1)

MONOSPACE (2)

size = 10

The font size in pixels (i.e. not in "points")

italic = False

If True, the text will be italic.

bold = False

If True, the text will be bold.

halign

LEFT JUSTIFIED (0): The text is left-justified to the point p.

CENTERED (1): The text is centered horizontally to the point p.

RIGHT JUSTIFIED (2): The text is right-justified to the point p.

Example 1: draw_text

fill

fill (Pixel value)

Fills the entire image with value.

value

A pixel value. This value may be any value the pixel type can support.

fill_white

fill_white ()

Fills the entire image with white.

flood_fill

flood_fill (Point start, Pixel color)

Flood fills from the given point using the given color. This is similar to the "bucket" tool found in many paint programs.

The coordinates can be specified either by two integers or one Point:

a:

The start Point.

color:

The pixel value to set for the rectangle.

Example 1: flood_fill((10, 58), 0)

highlight

highlight (Image [OneBit] cc, Pixel color)

Highlights all pixels on an image in given color that are black in the passed connected component. The connected component can be part of a different image, it must however lie within the image region.

cc

A one-bit connected component from the image

color

A color value (RGBPixel, 0-255, or [0|1], depending on the image type) used to color the cc.

Example 1: highlight

invert

invert ()

Inverts the image.

Example 1: invert()

Example 2: invert()

Example 3: invert()

remove_border

remove_border ()

This is a special case of the flood_fill algorithm that is designed to remove dark borders produced by photocopiers or flatbed scanners around the border of the image.