Viewing profile — jpap

Agreed; I do this all the time as well. I don't think it as "guessing" per se, I think of it as forming a hypothesis based on the intersection of my existing knowledge of the probl…

Unfortunately not when you're performing error diffusion, where the residuals are added to neighboring pixels. If you're doing it in the non-linear domain, you're going to get a di…

When I referred to "logarithmic domain", I'm not talking about a purely log/exp transfer function, but one that is "log like". Perhaps it is more accurate to say "non-linear domain…

This post covers a topic I've spent some time with in the past, and is generally a good overview but unfortunately gets the idea of "linear RGB" wrong. That means all of the result…

I'd also love to read the thesis, especially to see how they structured the lock. I recently wrote a readers-writers (subtree) lock for a K-ary tree and it was quite a challenge wi…

They would likely get another big speedup by doing this. iDCT gets faster as you perform a "DCT downscaling" operation because you require fewer add/mul [1]. You could probably go …

> TIFF and Exif (which JPEG is based on) are not tied to any particular codec and are extensible, so HEIF is not a game changer. TIFF is a great format but its ability for extensib…

> This format doesn't really blaze new ground (EDIT: it does in the sense that it defines a container format to express image-y constructs like still images and sequences of images…

> I'd be curious if the two "representations" are losslessly convertible, for example. They are: you could just extract the HEVC NAL units, and re-write them into a MP4 or QuickTim…

That's actually not a bad idea! The HEIF examples on the Nokia HEIF site do something similar; they implement a HEVC decoder (and do the HEIF container processing) all in JavaScrip…

While the full standard text and machinery can get quite complex, you can still construct relatively simple files housing a single image, thumbnail, and Exif that isn't that much m…

Yes! This is one of the motivations behind HEIF: it's codec agnostic and extensible. You can use HEIF with JPEG and AVC for example, or some new codec down the line. It's also exte…

HEIF is actually very closely related to MP4 (or really, the ISO Base Media File Format (BMFF); and historically, QuickTime which is what they are both based on). You are right -- …

My reference to "awesome" was in the sense of being fun. You could, of course, use a highly-compressed video instead, as some other sites do. Further, Disqus puts this animated GIF…

Michael, thanks for making contact by e-mail, outside of these public forums. As discussed over e-mail, I've created an in depth report showing that SnappyCam indeed takes full qua…

I'm so very happy to read your post! :-) I'm not usually one to post publicly either, but with practice I'm finding it comes more naturally. I do hope you dive in---the devil's det…

I considered doing this over a year ago. I was really intrigued by the algorithm and declared it was a distraction over getting the basic app solid first. I'd love to revisit it. I…

Agreed! I've got a good friend who is a skater and he reminds me of this often. Any good skating sites I might want to contact?

That really helps, thanks for letting me know about the disconnect extension. I've never used it, will check it out.

Very well said. I suspect Clarity on Camera+ is some form of Contrast Limited Adaptive Histogram Equalization (CLAHE). CLAHE came about from digital image cleanup of medical scans …

The Camera Roll will apparently host them, but not show them as animated. Unless you roll your own viewer, many devs suggest using an embedded UIWebView to animate it. Otherwise it…