how I can get my texture to appear exactly as is defined

[mspusch]

You need to set the appearance mode of your quad to viz.TEXNEAREST. Here is some sample code:

quad = viz.add(viz.TEXQUAD)
tex = viz.add(\'stim-green_123.png\')
quad.texture(tex)

#This will remove mipmapping of the texture
quad.appearance(viz.TEXNEAREST)