PyCairo 02 - Import a png to a svg

This script shows how to embed a png file in a svg with Cairo in PyGtk. The following techniques are adopted:

1. Cairo for graphics.
2. Cairo surface pattern.
3. Set pattern matrix for transformation.
4. Save the result into a SVG file.

Output

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Assume that a file named P6050019a.png is placed in the same folder as this script, a file named d01.svg will be generated by this script on the same folder holding the script, it will look like below.

Source Code

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import gtk, cairo WIDTH, HEIGHT = 400, 400 # place the png file at (pX, pY), # scale the png with scale factor pFac def placePng(pCtxt, pFilename, pX, pY, pFac): mpng = cairo.ImageSurface.create_from_png(pFilename) mw=mpng.get_width()*pFac mh=mpng.get_height()*pFac mPatt = cairo.SurfacePattern(mpng) mMatrix = cairo.Matrix(xx=1/pFac,yy=1/pFac, x0=-pX/pFac,y0=-pY/pFac) mPatt.set_matrix(mMatrix) pCtxt.set_source(mPatt) pCtxt.rectangle(pX,pY,mw,mh) pCtxt.fill() # Setup Cairo surface = cairo.SVGSurface("d01.svg", WIDTH, HEIGHT) context = cairo.Context(surface) # draw background context.set_source_rgb(0.95,0.95,0.6) context.rectangle(0,0,WIDTH,HEIGHT) context.fill() # place png placePng(context, "P6050019a.png", 50,52,0.25) # draw text context.move_to(50,50) context.select_font_face('Serif', cairo.FONT_SLANT_NORMAL, cairo.FONT_WEIGHT_BOLD) context.set_font_size(24) context.set_source_rgb(0, 0, 0) context.show_text("Can you see me?") context.stroke() # save svg file context = None surface.finish()