image is dark about plenopticam

[hahnec]

hi @hongyann ,

can you try to tick/untick the auto-contrast option in the settings window? does this improve the image brightness? let me know if this doesn't help.

[hongyann]

left one produced without auto-contrast, and the right one was ticked the auto-contrast option. the right image looks better. But I still think that the color of the picture is a bit distorted, that is, the generated picture looks color abnormal compared to the color observed by the human eyes.

[hahnec]

I absolutely agree. The problem lies in the colour metric handling of plenopticam which I yet covered only rudimentary. When I take your screenshot and do auto-white-balancing and auto-contrast in GIMP, I get something more similar to your reference image (see left: plenopticam+GIMP, right: other)

Note that applying enhanced colour treatment prior to refocusing will further improve the quality of the image. I will look into this. In the meantime, may I ask what software you used to generate the better looking reference images?

[hongyann]

the software I used is lytro power tool.

[hahnec]

That explains it :) I have added a new automatic white balance procedure similar to that used in GIMP. You can use it by downloading the master branch and installing via 'python setup.py install'.

I will also implement some histogram equalization in the upcoming days and expect further improvements from this. Keep you updated

[hongyann]

I have tried to download using 'python setup.py install' ， but there have been some problems during the installation process, I have not solved it. thanks for your answers, I will try it again.

[hahnec]

The install might have failed as your environment was missing the TIFF lib. I have now implemented a workaround using Pillow lib in case TIFF is not present.

I also added a first histogram equalization method to combat the dark image areas in the output images. You can use this method by ticking the contrast option in the current version of the develop branch (see below):

https://github.com/hahnec/plenopticam/tree/develop

You can install it with python setup.py install and call the GUI via plenopticam -g from the command line. Hope this helps. Let me know about further issues.

[hongyann]

with your develop branch, the produced image is better than before(left : before, right: produced now). thank you very much. and it will be perfect if you develop the color setting similar to our eyes.

when I process a stack of light-field images , I have a another question, that's how can I change the setting of plenopticam , for example: refocusing range, contrast automation. I have not found these settings in plenopticam -h .

[hahnec]

That's fantastic news! I pushed another update to the develop branch adding refocusing range options to the command line (use -h after re-install for details) as I was facing the same problem as you. Let me know if this works for you.

color setting similar to our eyes

Can u pls tell more about what you mean by this?

Best
Chris

[hongyann]

It works ! so cool !
I am sorry that I have given you a fuzzy suggestion. You just ignore it.
thanks for your answers. hope you can develop more and more excellent works.
best wishes!

[hahnec]

I am glad it worked for you. On a last note, I want you to know that all branches now feature histogram matching when contrast automation is ticked which results in more natural contrast. I added this feature yesterday. Thanks for sharing your experience which helped improve the software and please get back if you come across new issues.

Best,
Chris