iZoom, FZ200, LX7, FastStone - a few thoughts

Started Apr 10, 2013 | Discussions thread
Detail Man
Detail Man Forum Pro • Posts: 16,688
Re: iZoom, FZ200, LX7, FastStone - a few thoughts

Mikedigi wrote:

DoctorJerry wrote:

Very well said. It is my understanding that EZ Zoom ONLY takes a central portion of the sensor which is why ther is no image degradation. It does NOT add pixels anywhere. Both iZoom and digital zoom add pixels to the image to get back to their 12mp size.

In EZ, pixels are not added to the crop.  It is just a crop.

That is precisely his point.

Yes, iZoom adds pixels and uses iResolution to get the business done.

i-Zoom stretches the image-data contained within pixels out into other surrounding pixels - with particularly troubling results when the up-sampling ratio is not an integer value. Doing so seems (to me) silly given that such images are very likely to subsequently be down-sampled for display (which itself involves, up-sampling by interpolation, anti-aliasing filtering, and down-sampling by decimation).

There seems nothing magical about "i-Resolution". In fact, it actually reduces the resolution of any subject-matter existing in areas that it deems to be "low gradation". The net result is when fine detail exceeds the abilities of the image-sensor assembly to resolve it ("pixelation" effects), "i-Resolution" simply detail-smears it away. Rather unusual for a "sharpening" technique ?

It works well, better than a 3mp EZ file . . . trust me, I have used EZ for years, and I am a cynical #######.

From investigating how the FZ30/50 and LX3 accomplish "EZ Zoom", it appears that the chosen priority is that sensor-cropping is used, and down-sampling appears to only be utilized in cases of the very smallest "Picture Size" settings (i.e. 2.5 Mpixel and 3 Mpixel).

Why would an image that has been up-sampled (and then subsequently down-sampling for display purposes in the end, anyway) tend to look better than an image that has been down-sampled ?

More re-sampling (in general) means more artifacts (particulalry when non-integer ratios are used).

Not everything, that is new, is bad.

Extreme birders use it - why would they do that, if it was incompetent?

Just to chide you a bit. This "extreme birders use it" argument seems (to me) to be a bit of a "canard" (French for duck). People who endeavor to focus on any small object at distances may use such modes for reasons that relate to their ability to selectively focus on such subject-matter at all (despite the fact that less photo-sites are as a result being used in the CDAF system).

That alone says nothing in particular about the "image quality" associated with what they end up with. It may merely reflect a philosphy on their part that "some sort of capture is better than no capture".

Presumptions that whatever particular "image quality" (in their eyes) results is as a result universally "adequate" in the view of others simply because some persons choose what they get as an alternative to not being able to reliably selectively focus at all seem misguided to me.

The idea that if "image quality" (in one's own personal view) was poor, then others would surely forego attempting such captures and reject such results is not borne out in my experience.

DM ...

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