[mlizarra]

Hello All,
I am taking pictures on an N95 with a python script for S60 using take_photo(). The problem is that regardless of the setting I use for white_balance and exposure, I get _really_ over-exposed images. I was wondering if any of you had had the same problem? Or if it is a known issue. I have searched the forums and the web and have come up empty. Any hints or ideas are more than welcome.

Just in case here is the test code I am using:

import camera
import time

# I have used several settings for white_balance and exposure 
# (including 'auto') but seem to have no effect on the end result.
new_photo = camera.take_photo(mode='JPEG_Exif', size=(2592,1944), flash='none', zoom=0, exposure='center', white_balance='daylight', position=0 )
filename = "E:\\Images\\%sfoto_test.jpg" % int(time.time())
open(filename,'wb').write(new_photo)

I have also tried it with pys60 1.4.0 and 1.4.1. Also in two different N95s with the same result

Thanks

Mariano

[bogdan.galiceanu]

I tried your script and compared the photo to one taken with the camera of my N95. Yours turned out a bit darker, I wouldn't call it over exposed. Also on my 1.4.0, 2592x1944 is not supported, so I changed it to 1600x1200, but I really doubt this had any influence on the result.

[mlizarra]

Hello Bogdan,
Thanks for your response.Yes, I agree that the photo resolution has nothing to do with the exposure. Well, my pictures are MUCH brighter then the ones taken with the camera, so it means that I have something different (as in wrong). Could you type *#0000# on your phone and report back on the firmware version of your N95? Because apparently on your phone the white_balance = 'daylight' is having an impact and in mine it is not. Also I am using the python script shell self signed (i.e. I signed it to use the GPS) instead of the signed one.

You can see a picture taken with my script at http://www.aulati.net/mariano/Images/pic1.jpg, and this is inside a building, if I take one on the outside, the picture comes out almost totally white.

Anybody else out there has had a similar problem? Anybody has any hint on what I'm doing wrong?

Thanks!

[bogdan.galiceanu]

My firmware is 12.0.013. My python is unmodified (I didn't sign it).
Here's a comparison between your photo, and the one ofthe default camera.
http://i231.photobucket.com/albums/e...comparison.jpg

[mlizarra]

So now I am at a total loss, because I had hoped that you might have had a different firwmare version but it is the same. I assume the picture you took with the python script is on the left, so there is something diferent, but not sure what.

Now, if you notice the picture I took was with lots of light and yours seem to be inside your home/office and maybe that is why you are not getting overexposure, but nevertheless it is quite different to the one taken with the default camera application, when in principle it should not.. right?.

I tried uninstalling the python version and install an unisgned version like yours but still same result. Really weird. If I figure out something I will report back.

Any other ideas?

Thanks

[abhisin80]

Hi,

I am facing the same issue with take_photo. If I use the application outside a building then pictures get overexposed while inside the building they are much brighter but still recognizable.

Is it because that camera module takes around 7-8 secs to take a picture??

Does anyone else is also facing similar problem? Any directions...please help...

[noreli]

I discovered the same problem these morning on my N95 : photo are OK inside office, but much too exposed outside.
It doesn't depend on resolution or Jpeg_exif mode.
I've also the same firmware version.

Is it because of a carl zeiss driver bugs ?

To answer to your latency questions, I did different measures on different devices. Result are interesting.
On 2nd Ed with N70 : taking a photo takes less than 1 sec
On 3rd Ed with Nokia 6120 : it takes 3-4 sec
On 3rd Ed with N95 or N73 : it takes 6-8 sec

I suspect :
- There is a latency problem on the 3rd Ed
- There is another latency problem with mobile subset which has carl zeiss or autofocus capability...

[JOM]

Originally Posted by noreli

On 2nd Ed with N70 : taking a photo takes less than 1 sec
On 3rd Ed with Nokia 6120 : it takes 3-4 sec
On 3rd Ed with N95 or N73 : it takes 6-8 sec

Is the size of image same in all devices? For example do you take 2MB pictures in all cases? If not, then bigger image requires longer time, since it contains more data.

Size matters,

--jouni

[croozeus]

Originally Posted by JOM

Is the size of image same in all devices? For example do you take 2MB pictures in all cases? If not, then bigger image requires longer time, since it contains more data.

Size matters,

--jouni

Also it is resolution dependent, For example N95 has Resolution: 2582 x 1944 and N70 has Resolution: 1600 x 1200

Resolution, and thus the size matters

Best Regards,
Croozeus

[noreli]

I'm not sure that the problem is only the resolution because I did a new test on a N73 (autofocus carl Zeis) : same time as N95 : 7 sec where as the resolution is 3 millions pixel and not 5 millions pixel. It's more complexe with other factors.

I went further more in my tests and got other interesting remarks :

1) delay / resolution :

On 2nd ed, on a same device, the delay to take picture depends on the resolution that you programs for each pic.
On 3rd ed, these delay is the same for all resolutions.

with a N70 :
- pic 640x480 takes 1 sec
- pic 1600x1200 takes 3 sec

with a Nokia 6120 : 3 sec for all resolutions

with a Nokia N95: 7 sec for all resolutions

2) Time when pic is shoot : beginning or end of delay

On 2nd Ed the pic is taken at the beginning of the delay.
On 3rd Ed the pic is taken at the end of the delay : which is a very big drawback.

3) It's due to python interface because it's fast with C++ programs.


4) overexposed pictures is not in all carlzeiss optic, as I supposed before, because it's not occuring on my N73, which is carlzeiss autofocus.

[cassioli]

With both my 6600 and 6680 I always get picture much darker than those ones taken with standard built-in camera application.
Is there any workaround the "brighten" an image? I don't care speed, I just need to take a picture I have then to postprocess, which already requires some time...

I see that when I use built-in application, the image gets brighter and brighter within a few seconds while I'm holding the phone pointing into same directions, like the camera is "self-tuning" exposure. I guess this can't be done in python....

[ianw]

Has anyone found a solution yet? I too have tried using

camera.take_photo()

and the results are always overexposed when used outdoors.

N95 8G PyS60 1.4.3

[gaba88]

Originally Posted by ianw

Has anyone found a solution yet? I too have tried using

camera.take_photo()

and the results are always overexposed when used outdoors.

N95 8G PyS60 1.4.3

hi ianw
really sorry but i think the problem is with the camera itself maybe with the hardware.

[jplauril]

Originally Posted by cassioli

I see that when I use built-in application, the image gets brighter and brighter within a few seconds while I'm holding the phone pointing into same directions, like the camera is "self-tuning" exposure. I guess this can't be done in python....

This is really the heart of the matter. Currently the Python camera module reinitializes the camera when doing a take_photo call, and this resets all the adapted exposure parameters. After that it then instructs the camera to take a photo immediately, before it has had time to adapt to the lighting conditions.

This is a known defect:

http://sourceforge.net/tracker/index...55&atid=790646

...and we're working on it. The solution is to not reinitialize the camera before take_photo and to make sure applications run the viewfinder for some time before taking a photo to allow exposure parameters to settle.

[gaba88]

aha
this is the actual logical reason.
thanks jplauril for letting this bug known to everybody.