As I should have known, Belize is a small country in middle America. Next to Mexico and Nicaragua. I should have known because our fair traded Bananas are from Belize. But this video is not about Bananas, it’s about this image made in the shadow on a bright tropical day.
You see the problems in the original top-left. The background is a bit too bright and the woman way too dark. But two layers in overlay mode of an inverted desaturated copy of the image helped a lot. The final touches came by applying a layer for dodging and burning, also in overlay mode, and painting on it in white. All Croat to you? (Not Greek this week, see this blog entry.…) No problem, after the video you’ll understand.
Overlay mode does strange things, even the explanation in the help pages is a bit cryptic: “Overlay mode inverts the pixel value of the lower layer, multiplies it by two times the pixel value of the upper layer, adds that to the original pixel value of the lower layer, divides by 255, and then multiplies by the pixel value of the original lower layer and divides by 255 again.” I’ll think about a way to get that a bit easier to swallow.
The Linux Darkroom is an interesting collection of links and program descriptions. Definitely worth to look at – and perhaps you have something to add.
You can find the file used in this episode at the usual place.
The TOC
00:18 Off to Croatia – Slobodni Festival 2
02:02 The Linux Darkroom
02:40 Geography Lesson
03:22 High contrast image from Belize
06:04 – Try curves adjustment
07:48 – Overlay layer
08:47 – Overlay in monochrome
11:36 – Selective tweaking
17:12 Thoughts about episodes 50 and 49
20:39 The End
TOC made by paynekj
This work is licensed under a
Creative Commons Attribution-Share Alike 2.0 Germany License.
Tags: overlay mode, reduce high contrast, shadow
That was an interesting show.
About overlay mode
In GIMP this is identical to soft light mode due to a bug. Anyway, both modes result in a similar effect.
One can describe overlay mode as a mix of multiply and screen mode. Multiply mode darkens the image whereas screen mode lightens the image (it is in fact the inverse of multiply mode). Overlay mode thus darkens dark areas and lightens bright areas, in other words it enhances contrast. By inverting a layer however and converting it into B&W, its bright areas become dark gray/black and its dark areas become light gray/white. In this way one achieves the opposite: the layer in overlay mode will brighten shadow areas and darken bright areas; contrast will be reduced. This explains why the lady in the shadow became visible without washing out the sunny areas in the picture.
As you did in your show, overlay mode is also useful for increasing locally contrast by painting in black and white on a transparent layer in overlay mode: the dodge and burn layer. Black painting darkens whereas white painting lightens. As you surely know, dodging and burning are dark room techniques. It is not invented in the digital age.
Hope it helps.
Hello, Rolf!
I’ve only one word to describe this episode: Awsome!
Keep on!
@Serge; a really nice(!) additional explanation.
Yes, Serge is good at explaining such stuff!
This overlay mode is really difficult to get into the head – and to plan ahead. I just try it….
The show is cool….
I’ve used the overlay mode also to flat the skin on portraits….
paint with a nice color (taken from skin) over the face on a transparent layer…. set the layer to overlay and adjust the opacity down or double the layer….
with some experimenting you’ll get a flatter skin….
P.S. Paint only over the problem zones
retro
this is the image
[...] Episode 051: Contrasts from BelizeAs I should have known, Belize is a small country in middle America. Next to Mexico and Nicaragua. I should have known because our fair traded Bananas are from Belize. But this video is not about Bananas, it’s about this image made in … [...]
Unfortunatly the Linux Darkroom is closed, the link cannot be used any more. Does somebody know if it’s moved to another adress?