September 2017

Warning! Some information on this page is older than 6 years now. I keep it for reference, but it probably doesn't reflect my current knowledge and beliefs.

# Vulkan Memory Allocator 2.0.0-alpha.3

Wed
13
Sep 2017

I just published new version of Vulkan Memory Allocator 2.0.0-alpha.3. I'm quite happy with the quality of this code. Documentation is also updated, so if nothing else, please just go see User guide. I still marked it as "alpha" because I would like to ask for feedback and I may still change everything.

I would like to discuss proposed terminology. Naming things in code is a hard problem in general, and especially as English is not my native language, so please fill free to contact me and propose more elegant names to what I called: allocator, allocation, pool, block, stats, free range, used/unused bytes, own memory, persistently mapped memory, pointer to mapped data, lost allocation (becoming lost, making other lost), defragmentation, and used internally: suballocation, block vector.

Comments | #vulkan #productions #libraries #graphics Share

# What is Samsung phone doing to photos?! (sharpening a lot)

Mon
11
Sep 2017

I now use Samsung Galaxy S7 smartphone and I'm quite happy with it, except for the camera. I noticed that all the photos taken with it look bad. There is clearly something wrong with them. When I zoomed in, I noticed that the device applies insane amount of sharpening. Every photo looks like it was first filtered by bilateral filter (a kind of edge-preserving blur that is used for noise reduction) and then sharpening with intensity set to maximum, which causes annoying ringing artifacts around the edges.

I decided to make an experiment. I gathered all the devices I had access to that can take photos and I brought them to a place where I could photograph a building that has many sharp edges, plus some tram cables. It was the middle of a sunny day, so lighting brightness and contrast was high and devices didn't have a reason to apply too much processing to the photos taken. I configured all of them to fully automatic mode, maximum resolution and JPEG as output format (except Canon camera, where I forgot about it, so I actually made CR2 RAW that I later converted to JPEG). Devices I used for comparison were (click on each link to access original photo file):

When you zoom in to the building, you can clearly see that both Samsung phones applied very strong sharpening. It turns out this is a known problem. There is a discussion on Reddit, as well as YouTube video about it. Sony phone and DSLR don't have this effect.

Samsung Galaxy S6:

Samsung Galaxy S7:

Sony Xperia Z2:

Canon PowerShot G7X Mark II:

Nikon D90:

What's interesting is that the Canon camera also applied some sharpening, and did it even in RAW! (How can they call it RAW then?!) Fortunately in this camera it can be disabled: While in photo shooting mode, press MENU button, go to tab 6, select "Picture Style" and set it to "Neutral", so that the first parameter in the sequence of numbers (meaning "Sharpness Strength") is 0.

In Samsung phones this filter cannot be disabled :( The only way to take pictures without it is to use RAW, where it's not applied. To do it, while in photo shooting mode: swipe left, choose "Professional", enter configuration, select "Image size" and there enable "Save RAW and JPEG files". You need to enter "Professional" mode every time you want to take a photo. Then of course you need to process the image on your PC and convert it to JPEG, e.g. in Adobe Lightroom or other similar program, but there you can decide how much sharpening do you need (or none).

Comments | #photography #hardware Share

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