oh... I think I see what you are referring to. The second image should have the regular lenna image, not the negative? Ben Root On Fri, Feb 27, 2015 at 5:39 PM, Benjamin Root wrote:

It is Friday evening here... I must be really dense. What bug are we looking at? Is this another white-gold vs. blue-black dress color thing?

Ben Root

On Fri, Feb 27, 2015 at 5:33 PM, Sturla Molden wrote:

...

Somewhere... But where is it?

NumPy, SciPy, Matplotlib, Cython or ipython?

I am suspecting ipython, but proving it is hard...

http://nbviewer.ipython.org/urls/dl.dropboxusercontent.com/u/12464039/lenna-...

Sturla

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On 27/02/15 23:39, Benjamin Root wrote:

Is this another white-gold vs. blue-black dress color thing?

No. It is what you said in you next post. I hate that dress image. The first time I looked at it it was white and gold, then it became blue and black, and the third time it was grayish blue and bronze. I'm not going to look at it again, it might have exploit code to plant malware in my brain. Sturla

Ben Root

On Fri, Feb 27, 2015 at 5:33 PM, Sturla Molden mailto:sturla.molden@gmail.com> wrote:

Somewhere... But where is it?

NumPy, SciPy, Matplotlib, Cython or ipython?

I am suspecting ipython, but proving it is hard...

http://nbviewer.ipython.org/urls/dl.dropboxusercontent.com/u/12464039/lenna-...

Sturla

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On 28/02/15 00:04, Robert Kern wrote:

When plt.imshow() is given floating point RGB images, it assumes that each channel is normalized to 1. You are mixing a 0..255 image with a 0..1 image. Divide `lenna` by 255.0 before you stack it with `_dct`. Or multiply `_dct` by 255 and cast it to uint8.

Right. Thanks. Since it's past midnight this probably means I should not touch the computer until my brain has rebooted.