or “How to drive away the evil skull” At all times main memory was one of the most limited resources in computing. Although from 20 years to now the memory setup of a typical desktop PC has increased by a factor of several thousands (from less than a megabyte to a few gigabytes), we still need to consider how to efficiently handle that resource. The reason of course lies in … Continue reading
this is one of the oldest modules in darktable. it appeared to me that it probably lacks an example to discover how useful it can be.. so here goes the example. this started off to be a wrapper around the gegl:whitebalance operation, which works in Lab color space and is able to give dark and bright colors a different color tint, interpolating between the two for mid tones. so suppose … Continue reading
or „If one slider is not enough“ Diligent readers of our small blog series are already aware of the blending feature that darktable offers as part of many modules. Instead of just handing over their result to the subsequent module in pixelpipe, “blending modules” take a moment to reconsider. Based on the blend setting they will take their original output together with their input and do a re-processing. As an … Continue reading
Many readers will have already heard about GPU processing and the fact that darktable can make use of OpenCL to improve performance. As we still lack a detailed documentation of that topic, please find here a few explanations and howtos. The Background Processing high resolution images belongs to the more demanding tasks in modern computing. Both, in terms of memory requirements and in terms of CPU power, getting the best … Continue reading
disclaimer: this is only to tease you and will not make it into the next release, but the one after.. when reading gui-guidelines, most of them seem to be too general, or too specific for a certain kind of programming environment (gnome and gtk, qt, etc). for our purposes, i found the fundamental principles of the bauhaus school to be more appropriate. radical simplicity, no unnecessary shape or line, such … Continue reading
One of the remaining shortcomings of digital cameras is their rather low dynamic range in comparison to analog – especially black-and-white – film. Scenes with strong differences between highlights and shadows are very difficult to capture. Even if they are exposed properly with no blown-out highlights they will too often only give acceptable results after extensive post-processing. Fortunately, darktable is progressing with a high pace. Some days ago I wrote … Continue reading
Outdoor photographers are often confronted with unfavorable light conditions. This often entails too high contrast. Two of the most frequent consequences are blown highlights and deep shadows in your digital images. Overexposed highlights are challenging to repair in digital post post-processing, still darktable offers a decent set of valuable tools as long as you take your pictures in raw (see Jo’s blog post “why you want raw”). Fortunately, it’s much … Continue reading
or “How to bring the jungle back” Since its early beginnings darktable has a tone curve module that is able to alter the gray level distribution of an image. Recently we did an enhancement: tone curve is now able to control the full Lab color space with separate curves for the L, a and b channel. People who are used to curve tools in RGB, at first might get puzzled … Continue reading
or: how to rescue your shot after the fact. also: how to use color zones for black and white. sometimes i’m surprised by what kind of data is hidden in my raw images, and i want to pass this on to those of our users who happily take pictures in jpg. actually it’s just a short story about a typical communication problem between me and my camera and the way … Continue reading
you might have noticed our equalizer tool, and been confused by it and the many controls. that’s probably partly because you didn’t see a similar thing before, we had to develop it first. very short history behind the ui is a powerful frequency domain processing technique, based on wavelets. the most commonly used wavelets are based on the lifting scheme [swe97], work in a data-independent way, and are decimated (i.e. … Continue reading