Search found 68 matches

by MachineCode
Fri Feb 01, 2019 2:33 pm
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Re: Floating Point color

This is what the color space transforms look like. Compared to the 8:8:8, the 4:4:4 has banding. In the third image, it is still 4:4:4, but weighted dither applied to the lsb's of the color components. The banding is gone but there is some graininess visible.

sky-set.png
sky-set.png (141.06 KiB) Viewed 1213 times
by MachineCode
Wed Jan 30, 2019 1:26 pm
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Re: Floating Point color

Brain snap when I typed that above. i was mixing up the forward and reverse conversions. col_int_8 = floor(255.9 * col_fp) col_fp_4bit = floor(15.9 * col_fp) / 15 -- that gives 0 --> 1 in the floating point range, clipped to a 4 bit space. It just goes to show that the continuous representation of c...
by MachineCode
Wed Jan 30, 2019 12:57 am
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Re: Floating Point color

Currently I am using

Code: Select all

 col_int = floor(255.9 * col_fp /256) 
That effectively divides the color space up into 256 regions and excludes 1.0 from giving the out of range 9bit value of 256.
by MachineCode
Wed Jan 30, 2019 12:17 am
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Re: Floating Point color

Let me just explain why I was looking at this and became confused. I have been working on a drawing engine that uses 16 bit instructions to do basic primitive things - like set pixel, draw block. Because of the 16 bit format, 4:4:4 color (12bit) is the native format, so to encode an image you first ...
by MachineCode
Tue Jan 29, 2019 2:11 pm
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Re: Floating Point color

I agree that the exact values of the 00 and ff colors don't really matter because you can't see them anyway. What is important is when you wish to modify or mask a subset of the color range. With fp, you need to specify a fp range. With fractional integers, you can reliably specify color regions wit...
by MachineCode
Tue Jan 29, 2019 12:25 am
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Re: Floating Point color

I suggest you learn more about FP numbers to be more familiar with their format, their limitations and their quirks. My point was that the inclusion of 1 in the fractional range makes sense from a pure mathematical pov, but introduces problems when mapping to real world DA convertors which select be...
by MachineCode
Mon Jan 28, 2019 2:54 pm
Forum: General
Topic: Floating Point color
Replies: 15
Views: 3382

Floating Point color

Over the weekend I have been do some experiments with color spaces and converting to more restrictive color schemes like 4:4:4 (12bit) or 3:4:3 (10 bit). The use of fp 0-1 for each component seems to make sense in a language like Lua, and it has been widely adopted, but it does have some complicatio...
by MachineCode
Tue Jun 12, 2018 2:32 pm
Forum: General
Topic: Could LÖVE run on a Raspberry Pi 2B WITH x11?
Replies: 17
Views: 2833

Re: Could LÖVE run on a Raspberry Pi 2B WITH x11?

If you use Raspian on a RPi, then enable OpenGL and Love 0.10.2 will run really well. The easy way to do this is to install love from the RPi repository (still 0.10.2 with the latest Raspian). This installs all the dependencies and should get you a Supertoast if you open a term and type love. The op...
by MachineCode
Mon Mar 12, 2018 2:30 pm
Forum: Support and Development
Topic: Raspberry Pi OpenGL and 0.11
Replies: 2
Views: 755

Re: Raspberry Pi OpenGL and 0.11

OK thanks. That is good news.
by MachineCode
Mon Mar 12, 2018 4:38 am
Forum: Support and Development
Topic: Raspberry Pi OpenGL and 0.11
Replies: 2
Views: 755

Raspberry Pi OpenGL and 0.11

One of the great things about 0.10.2 is how well it runs on a Raspberry Pi 3 with the OpenGL driver. I haven't found anything different from a normal Ubuntu or Mint x86 installation. 60fps is normal as long as you don't do ridiculous things. In fact, I have been using Raspberry Pi 3 as speed test fo...