On Tue, 11 Oct 2022 19:39:38 -0400, Paul wrote:

> On 10/11/2022 10:30 AM, Zitelli wrote:
>> Herbert Kleebauer wrote at Tue, 11 Oct 2022 10:07:26 +0200 :

....

>> I installed that commercial ransomware which they say is free for personal
>> use. Somehow either Irfanview talks to that codec or that codec talks to
>> Irfanview because the images finally came up.
>>
>> To convert that hard to read HEIC format into a sane format, I put all the
>> HEIC files into a folder and opened one of the HEIC files in Irfanview and
>> hit "b" and then I had to change the default "Files of type" to "All files"
>> before I could press the "Add all" button. Then I selected the "Batch
>> conversion" circle and the "Output format" of "JPG-JPG/JPEG format" where I
>> was surprised how long it took per file for Irfanview to convert a day's
>> worth of HEIC photos to the sane JPEG format.
>>
>> If someone asks me in the future, my recommendation is the same as Paul's
>> which is "Don't use it" but if they receive a batch of HEIC files, my
>> recommendation for them is to convert them to a sane commonly readable
>> format (as shown above) as quickly as possible.
>
> I would not do a victory lap quite yet.
>
> For any converter, you need to verify whether it gives
> all the images within each container.

There is another twist.

JPEG is a lossy format. I assume that HEIC is also lossy (it has to be, impossible to compress that lot without being lossy). And I guess there is an extra loss in the format conversion.

--
Cheers, Carlos.

"Carlos E.R." <robin_listas@es.invalid> wrote

| There is another twist.
| | JPEG is a lossy format. I assume that HEIC is also lossy (it has to be,
impossible to compress that lot without being lossy). And I guess there is
an extra loss in the format conversion.
|

Did you look at Paul's image link? In an earlier
discussion he posted samples of the rowhouse picture.
The HEIF version was notably distorted, but it wasn't
so noticeable at a casual glance, It was as though some
of the houses had been partially crushed. There seems
to be some kind of calculation to decide what data
can be skipped, similar to how JPG calculates what color
detail can be skipped without losing the image.

It's an interesting way of looking at priorities: It doesn't
much matter what the image is, so long as the viewer gets
a general idea. The implication is that people are usually
only looking at images for cues to preconceptions, so we
really just need a kind of icon image. For example,
if a JPG is clear enough to see that it's Joe Biden standing
with Putin, we consider the image adequate so
long as it communicates merely that data. Typically, if
you zoom in just slightly on such an image it will degrade
to a color grid of rectangles.