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Old Aug 22, 2003, 5:15 PM   #1
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Default Interpolated Image

I am seeing more digital camera's with an interpolated image size. I'm thinking that I should be able to store the photos in the lower resolution, and then accomplish the same interpolated image quality with software. Is this true? Is there any real advantage to having this interpolation in the camera?
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Old Aug 22, 2003, 6:39 PM   #2
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Interpolation is a process of averaging 2 or more points of real data to assume a further point of data. Since the new data point is not real, there are possibilities for the processing to get it wrong. Interpolation is the processors 'best guess' so it's best to avoid it, but it can be a way of selling something and you should still compare like with like, and certainly not pay proportionately more for interpolated output when doing comparisons.

I think what you mean't to say was 'you should be storing in the highest real resolution of the camera, and then 'down sampling' in editing (which is not the same as interpolation) to produce images for say printing, viewing on a monitor, emailing or the web'.

If you don't do this, you risk having poor images which you may want to enlarge for printing or crop at a later date. Hard disc storage space and CDR's are very cheap!
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Old Aug 22, 2003, 10:19 PM   #3
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I was referring to the new Fuji S5000 which has a 3mp native resolution and a 6mp interpolated resolution. For me, I wouldn't need more than 3mp very often, and would probably shoot most pictures at this resolution.

What I was wondering about was if I did want a higher resolution photo to make an enlargement, is there a software that can increase the filesize to help keep the enlargement from appearing pixelized?
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Old Aug 22, 2003, 10:48 PM   #4
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It's a marketing gimmick like digital zoom...this way they can say they got 6mp. You should use the "real" sizes only...that way you not only save on memory, but you get a better image, plus you can always do it on the computer later and get back to the original unaltered image if you make a mistake.
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Old Aug 23, 2003, 7:05 AM   #5
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Check out http://www.fredmiranda.com/SI_Pro_Plugin/

This is the programme you need.

David
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Old Aug 23, 2003, 7:44 AM   #6
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Because of the different layout of the sensors on Fuji's Super CCD's the camera itself actually does the interpolation better than any photoeditor out there. The actual resolution of the image taken with Fuji's 6MP corresponds image taken with real 4MP camera.

For my experience when the 6MP images are reduced to match to the size of 3MP they look just a little better with more details and natural sharpeness.
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Old Aug 23, 2003, 8:46 AM   #7
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Dale Cash...........You need to read about Fuji's terminology. In a horizontal and vertical sense they are saying the sensor 'native' resolution is 3Mpix. But they rotate their sensor through 45 degrees.So their 'interpolation' isn't quite all averaging, because there will be extra sensor pixels that align and the sensor output data is not a true 'native' copy of the image pixels. The way to look at it is in Fuji's case the sensor includes the interpolation chip. This is why you will never see a RAW TIFF at 3Mpix - That's not what's coming off the post processed sensor. Anyway, the best interpolation is being done on the raw sensor output, so the information will be truer than if you did it in PS after the camera processing, white bal etc.

Which is why I was trying to say that Fuji's 6Mpix is the same starting point for all resolutions the camera offers, but they've internally down sampled it to 3Mpix in this mode and applied more sharpening.

By starting with the 6Mpix Fine (soft sharpening) you are more in control to sharpen according to how much you like and what suits the output.
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Old Aug 24, 2003, 8:53 PM   #8
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If you want to interpolate, use Genuine Fractals 3.0 from Lizartech Software, it uses software adapted from that used by sattelites to compress their images for transmission back to earth :shock: .
The interpolation software is specialised, it does some sort of 3-dimensional maths, and can increase file size by upto 600% without degradation. I use it myself and highly recommend it.
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Old Aug 25, 2003, 12:19 PM   #9
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A very good free software package is irfanview. Under it's resize/resample menus, you will see the option to use a very sophisticated Lanczos Filter Interpolation algorithm.

I've found it very useful for use with my old Nikon Coolpix 950 (2 Megapixels). It lets me crop an image some, and still get great 8x10's. BTW, the previous poster mentioned Genuine Fractals. I can remember when Nikon advertised the 2 Megapixel Nikon 950 as being able to produce excellent 11x14's (because of Genuine Fractals). LOL Now, everyone seems to think that you need much higher resolution to get even 8x10's.

Of course, subject matter can make a big difference in perceived quality -- as interpolation does not add detail. But, for portraits -- even cropped some, I've gotten great 8x10's using interpolation on images from a 2 Megapixel CP 950.

Without it, any cropping at all, and degradation is immediately obvious at larger (i.e., 8x10") print sizes.

Irfanview also has a very good redeye reduction feature, that lets you specify how much reduction to apply (under the effects browser menus).

With many other packages (even ones I've paid for), you tend to have either not enough correction (too narrow of a range, for the specific shade of red present), or too much correction (leaving "black holes").

Irfanview leaves the eyes looking very natural, including non-red light reflections from the pupils.

It also has many other features (view EXIF data, image adjustments, etc.) The best part of all, is that it is totally free!

You can download here: http://www.irfanview.com

BTW, here's an example of an image with redeye from my Konica KD-510z (same camera as the new Minolta DiMAGE G500):

http://www.pbase.com/image/19295353/large.jpg

Here it is after using a conservative -20 Redeye reduction with irfanview (to make sure the eyes didn't end up looking like "black holes". -- Look at the "original" size images to see the eyes better.

http://www.pbase.com/image/19653334/large.jpg

For my thoughts on how well the Fuji's Interpolation works, see my response (under Jim Cockfield) in this forum thread at megapixel.net:

http://www.megapixel.net/phpBB2/viewtopic.php?t=8420

P.S. -- some photos from my new Konica KD-510z are here (world's smallest 5 Megapixel Camera with a 3x Optical Zoom):

http://www.pbase.com/jcockfield/konica_kd510z
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