The silver halide film grain has an unique look that introduces some texture in smooth image areas, where digital imagery may look synthetic and too clean. Emulating this effect in digital photography cannot be done by simply adding gaussian or poissonian noise to the image, since silver halide grain has varying shapes and sizes. There are two techniques to do it :
I have spent the past month working on an AI-based search engine.
When you go on darktable sub-Reddit, you will find the question “why do lighttable’s thumbnails look different from darkroom preview” asked every next week. The question is answered many times on this sub-Reddit, on various forums, and I even put the answer on the main Readme file, displayed on the Github main page of [...]
The core basics of design are to know for whom you design, that is who are the users of your solution, what they expect and what they need. It is also necessary to assess if the actual user of your product is the one you designed it for in the first place, that is, who is missing from your user base, to avoid the [...]
There is this mantra that I have been hearing too much in my life : “don’t reinvent the wheel”. People mean that as a metaphor trying to discourage you from redoing something that is already done, and by that they actually want you to use whatever software application or library instead of coding your own, as if it was automatically a time and resource saver. [...]
The opensource ecosystem is keen on its mantras. One of them is that being an opensource dev/maintainer is a thankless unpaid job. And while that may sound like a selfless act of benevolence, there is another way of reading it : a selfish way of avoiding professional responsibility, while still exerting some amount of power and decision. Which is the egg and which is the [...]
In image processing, retouchers may want to apply a saturation boost on specific hues only. Typically, uniform saturation corrections follow a basic linear transfer function $sat_{out} = gain \cdot sat_{in}$, where $gain$ is a real positive constant. To target specific hues, we simply rewrite $sat_{out}(hue) = gain(hue) \cdot sat_{in}$ where $gain$ is then a function. The most common way to [...]
There is one thing you will find on the home page of pretty much any open source (call it libre or free if you will, those lines are blurred) image editing software : the promise that it is, somehow, suitable for professionals. Marketing has abused that word for decades, it is only natural that it should affect non-commercial and non-profit projects as well, just to try [...]
The saturation control of pretty much all image processing software is an unfortunate misnomer, to say the least. It actually controls either the chroma in Ych-like spaces (computed from CIE Yxy 1931, Yuv or YCbCr spaces), or some remote idea of saturation as used by HSL spaces, which are essentially a polar rewriting of RGB coordinates (usually expressed in sRGB space).
The “saturation” as defined [...]
I’m a responsible web designer, and as such, since WordPress (finally) accepts media uploads of image/webp MIME type and since all web browsers newer than september 2020 (even Apple Safari \o/) can display it, I have been moving my photos library to WebP. After all, when you create content, the least you can do is to also provide the smoothest user experience around it.
WebP falls [...]
This page is inspired by the Munsell book of color. It aims at showing the sRGB gamut volume (all the visible colors that can be encoded as sRGB triplets), projected into a perceptually uniform lightness/chroma space (using JzAzBz color space[^1]), and sliced across hue planes. The sRGB space is the lowest common denominator of all general-audience screens, and is deemed fit to choose colors for [...]