My Camera Quality Metric
 

I've been looking at lots of samples of pictures taken by the n900 camera. They all look really good and blow other cell cameras out of the water.

I know its not meant to be as good as a high end point and shoot, and maybe compete with the lower end ones.

However, my judge of a camera's quality is generally if I find a sign with some text on it that is just out of my readable range (which I have 20/17 vision) and I snap a picture of it on the camera at base optical zoom, then I should be able to go to the saved image, zoom in on the text and be able to read it, even if it is only just better than what I could do with my eyes.

So basically in my opinion a good camera should capture more detail in a scene than even my eyes can.

Does the n900 camera pass this test? With only 5 MP I'm thinking maybe not, but anyone care to comment?

Re: My Camera Quality Metric
 

5 MP shouldn't be a limiting factor. My LG Viewty* is 5 MP and it passes this test.

But your "test" can only be used to compare camera resolution when the cameras have the same field of view (in degrees). Otherwise, the one that is more "zoomed in" (narrower field of view) will be able to more easily show the fine detail.

Regards,
Roger

*Actually I should say "my daughter's LG Viewty", because I gave her the phone in anticipation of having an N900 for myself by the end of October (sob!).

Re: My Camera Quality Metric
 

Note that the N900 only crops (not scales) when you shoot in 3.5mpix.

Re: My Camera Quality Metric
 

What I have noticed is this - images that are taken at 5MP should be fairly large - instead we end up with ~800k images. My suspicion is that Nokia have done the same thing Google did in order to get speedy writes to the sdcard. They have dropped the Jpeg quality to < 100%

Its difficult for me to be able to verify this unfortunately. Anyone with a little more knowledge than me care to weigh in on this?

Re: My Camera Quality Metric
 

I wonder if that is true, and if so would be nice to have a way to change that setting somehow (assuming it can be changed at all).

Re: My Camera Quality Metric
 

I checked the jpg info
the jpeg compression is between 70% and 85%
it is very high.

Re: My Camera Quality Metric
 

Ahh ok - thats a shame then. I wish that was something we could adjust. While 70-80% is adequate it is always nice to get pictures in lossless (or close to) format as well.

Again I am sure that this was done to expedite the speed of writes to the sdcard, but I do wish they had given us the option.

Re: My Camera Quality Metric
 

The jpeg quality is settable via a config file - 100% gives 2-3mb files, but the quality is not THAT different..

Re: My Camera Quality Metric
 

/etc/gdigicam/gdigicam-camerabin.conf ? Interesting!

Re: My Camera Quality Metric
 

Yes. Needs enabling and restarting the camera daemon. DISCLAIMER: Do NOT touch any of that stuff unless you are ready to reflash if things go south.

Re: My Camera Quality Metric
 

There's always time for flashing :). Thanks for the info, I like to have control :)

Re: My Camera Quality Metric
 

Can someone give me more easier instructions to get the uncompressed file?
Of course i read and know the disclaimer.

Thanks

Re: My Camera Quality Metric
 

Ooh, that's really neat. You could change the image format to something other than jpeg if you wanted to using that file (to anything GStreamer supports, it looks like). Nice.

Re: My Camera Quality Metric
 

Has anyone tried making changes to the config file, and if so, did you at any time go beyond specified parameters and cause issues? Would love to know success/failure in this regard.

Thanks, Thor

Re: My Camera Quality Metric
 

I changed it to 99% and the pics seem (quite a lot) better to me. I'd do some before and afters, but I'm having problems SSH-ing into the phone.

WS

Re: My Camera Quality Metric
 

OK, I've taken pics at 80% and 99% compression.

80%
99%

The 99% one is nearly five times the file size, but I can't see much difference between them, except maybe on the kindling on the right.

WS

Re: My Camera Quality Metric
 

I like my pillows, i'll leave the compression low.

Re: My Camera Quality Metric
 

Joshv06, good one!

Re: My Camera Quality Metric
 

Yeah. I played and tweaked the settings quite a bit, and tested various things - the default setting is pretty good compromise - so I ended up leaving it at where it is. The more important thing for good quality pictures is to use enough light. So instead of pondering jpeg compression (which is really not making a significant difference here) - add more light. Move closer to the window, add a desk lamp (and set white balance accordingly to tungsten if it is such) or be creative some other way. This is what makes the shot initially less noisy, thus requiring less noise reduction. This makes the most difference really.

I'll be writing a quick wiki tutorial about my experiences with the N900 camera.

Re: My Camera Quality Metric
 

Indeed if you pay close attention, at 80% compression you can see more artifacts than 99% compression....but the difference is not big.

Re: My Camera Quality Metric
 

diffraction makes most of the 5mpix unused. all the details disappear and small sensor makes much noise and noise removal removes rest of the details.

there is about nothing significant to do with software with cameras integrated to cellphones etc. and decreasing jpeg quality probably makes no realistic difference....

a small example:
you can stretch this heavily cropped (100% crop) image taken from 4mpix raw image data about 2-3x or more and the quality is better than with N900's 100% crop.

http://peltsip.pp.fi/samplet/tikanperse1.JPG

Re: My Camera Quality Metric
 

in wide mode the camera is better than 4/3 mode.

In the 5 mp mode, the images are not vivid such as in 3.5 mode.

I did many test and when i will time, i post some example