GIMP/C2/Adjusting-Colours-Using-Layers/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:22 | Welcome to Meet the GIMP. My name is Rolf Steinort and I’m recording this in Bremen, Northern Germany. |
| 00:29 | In the previous edition I got this image here, after editing. |
| 00:33 | And today, I think I should do something to set the colors |
| 00:39 | because this image is too green. |
| 00:41 | There are lot of ways to adjust the color and one of them is the Curves tool. |
| 00:47 | I click on the Curves tool in tool box and then I select the Green Channel and pull the curve down. |
| 00:55 | Now you can see that the colour channels and the fog in the image looks like the real fog. |
| 01:02 | Now, I have to adjust the curve in such a way that I get an image which is gray and not green or magenta. |
| 01:13 | I don’t want to use Curves tool because it damages the details of the image and I can’t correct the damage afterwards. |
| 01:23 | I could use the Undo tool but I will have to redo all the steps after that. |
| 01:28 | So, I want to have something that will not damage the image and I can adjust later on. |
| 01:34 | There is such a way which uses a simple filter with layers. |
| 01:39 | So, I have opened here the layer dialog. |
| 01:43 | You will see here background which is our original image. |
| 01:47 | And I simply add a new layer and I select White in Layer Fill Type and give it a name, color correction green. |
| 01:59 | Now my image is fully white but I can change the layer mode. |
| 02:05 | The 'layer mode' is an algorithm which combines the two layers i.e the original Background layer and the newly created layer. |
| 02:16 | So, I choose here the Multiply mode. |
| 02:22 | And you get the original image back, as it was before. |
| 02:27 | The Multiply mode, multiplies the pixels from the background to the pixels from the foreground and divides the result by 255. |
| 02:37 | And in a white picture, all the color channels are 255; so multiplying by 255 and dividing by 255 gives the starting point i.e. Background. |
| 02:52 | But if I reduce one channel in the new layer, it will be reduced in the background also because multiplying by say 200 and dividing by 255 gives less. |
| 03:06 | Now I want to select such a color which has a reduced green channel. |
| 03:12 | Here I have black as foreground colour which I change to background colour and white as foreground colour and you can see that red, green & blue all colour channels have same value i.e 255. |
| 03:31 | By the way, don’t be distracted by the colours on the slider here. |
| 03:36 | This is not blue, this is yellow but when I slide this down to a certain point, you see that colours in all the sliders change automatically. |
| 03:50 | Ok, I select the green slider here and pull the slider to say something around 211. |
| 03:59 | And I pull the colour which I got as my foreground colour into my image and I get the result which is way to magenta. |
| 04:10 | But I can adjust the intensity of my green reduction with the help of the opacity slider. |
| 04:19 | And when I go back to zero, I get the old image and when I pull the slider up I can reduce the green channel in the image and also avoid getting magenta into the image. |
| 04:35 | I think this looks quite good. |
| 04:38 | By using the Layers tool, I can do changes anytime I want to and also I can do fine adjustments when more layers are stacked onto it and the change will stay even if I change something in underlying picture. |
| 04:55 | There are still changes to be made in this layer as now it appears gray and I want to add a bit of blue. |
| 05:03 | Again I follow the same procedure and make a new layer and called it color correction blue. |
| 05:11 | And now I want to add a little bit of blue. |
| 05:15 | For adding blue in the image, I use the Screen Mode which is little bit more complicated than Multiply mode. |
| 05:24 | In Screen mode, the colors are first inverted and then multiplied and divided and quite complicated. |
| 05:33 | Let me change the foreground colour to black and add the colour I want to add directly and now I have to add a little bit of blue. |
| 05:43 | So, slide down the blue slider a bit. |
| 05:47 | And drag the colour into the image. |
| 05:51 | This, here, is supposed to be blue which looks still like black but it is very dark blue. |
| 05:59 | Look at the image here and when I switch this off, you see the change. |
| 06:04 | The image is definitely bluish. |
| 06:08 | I can switch off both the new layers and by that you get the starting point. |
| 06:13 | When I click on the first layer, we see the reduced channel of green and when I click on 2nd layer it adds a bit blue colour. |
| 06:22 | I think this is too much blue so I reduce the opacity. |
| 06:27 | I think this looks good. |
| 06:30 | I can adjust it later on, all the time. |
| 06:33 | The Layers tool is very powerful because you can create layer upon layers and in each layer you can change the pixels which are coming up from the lower layer. |
| 06:44 | Possibilities of doing the correction is limitless and you can do it whenever you want. |
| 06:51 | Perhaps here you can slide the opacity slider a bit down to get a good colour and you can play with these sliders which give real hand full of possibilities to change the color here. |
| 07:05 | I think I have to cover the Layers tool in detail on a special show but for today this is enough. |
| 07:13 | This is Hemant Waidande, dubbing for the Spoken Tutorial project and I hope to see you around next time. |
