[Ben Holmes]

Mark Ulrik Wrote:

Ben Holmes Wrote:

Mark Ulrik Wrote:Kindly explain what you mean. Last time I checked, JPEG was a file format for raster images.

Here is just one of thousands of online explanations...

Now, where's your admission that your pixel counts are nonsense?

In other words, you have no clue.

I just proved otherwise. I cited for my statement... you still refuse to cite.

You're now trying to deny that JPEG is not a lossy compression method.

You won't cite for any such claim. You CANNOT cite for a falsehood.

Mark Ulrik Wrote:Let me help. When I use the expression "pixel count," I'm talking about letting my raster graphics editor (in this case Paint.NET) do the work for me. Its line tool gives me the length in "pixels" (not a count, but rather a measure of length, using the width (or height) of a single pixel as unit):

Can't be done on a photo that's not raw data. You no longer HAVE the original photo. You can get close, but anyone asserting distance at the pixel level simply doesn't know what they're talking about. So you're getting schooled... you ignored my cite (probably didn't bother to click through) so here's a few bits I collected online to educate you:

Quote:Remember, because the image is compressed and saved to JPEG which is a “loss” file format, much of the initial image information and detail is discarded and cannot be recovered.

Quote:JPEG is "lossy", meaning that the image you get out of decompression isn't quite identical to what you originally put in.

Quote:JPEG has a hard time with very sharp edges: a row of pure-black pixels adjacent to a row of pure-white pixels, for example. Sharp edges tend to come out blurred unless you use a very high quality setting. Edges this sharp are rare in scanned photographs, but are fairly common in GIF files: borders, overlaid text, etc. The blurriness is particularly objectionable with text that's only a few pixels high. If you have a GIF with a lot of small-size overlaid text, don't JPEG it.

Now, explain to everyone how you're measuring distance in pixels WHEN THE PIXELS MAY NO LONGER EXIST.

Or run again...

P.S. For anyone that wants to learn, simply take a lossless photo, such as a PNG or GIF, resave it as a JPG - then load both photos at the same time, zoom in close on some particular feature in both photos, and note the difference. The difference will be more dramatic as you increase the compression level of the JPG. Mark doesn't want to do this, since he'd learn who's telling the truth, and who's ignorant of photo compression.