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LAB processed image


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Original and LAB colour space processed image.


Converted image to LAB space, added Curves adjustment layer, improved contrast using the L curve,
applied slight unsharp mask to L channel, moved A and B curves by equal amounts of 0.25 at both ends
(left point to 0.25 and right point to 0.75) Applied Filters>noise>dust and scratches at 1.7 radius
only to A and B channels.

The above made image sharper, less prominent colours deeper and removed little bit of colour noise that was present.

Based on details from one of the best authors on LAB colour space : Dan Margulis

First image is LAB processed image and second is original

gull LAB processed.jpg

gull orginal image.jpg

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  • 2 weeks later...

Here is another image processed similarly. The basic workflow is as below.
Simple mask is used for the flower. So from the A&B colour adjusted layer, only the flower was passed through.
In the Lightness channel, sharpening was done  and a mask was used to pass through the flower alone.
In another layer, L channel was adjusted to make the full image bright and the same mask was used to pass through the flower only.
Again in another layer, full image was made darker and inverted mask was used to pass the background except flower.
No blurring of A&B channel was done because there was no colour noise.

The colour separation and vibrance seems to be better when done in LAB. It may be possible to get same result in RGB mode
but could be more difficult.

First image is LAB processed, 2nd image is original. Camera Nikon D3100, Lens was a Sigma 70-300 DG macro. A humble camera system.

LAB processed.jpg


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@zaflemos Welcome to the world of Affinity Photo. It is a very powerful software and also have Affinity Designer and Affinity Publisher for 2D vector and publishing related work, respectively. Your above attempt on sky replacement is a good start but requires some more refinement. Basically, masks have to be used and masks needs refinement to ensure good blending of all the layers. There are ways of tuning masks wherein manual tweaking finally required is a minimum. I am giving some links below. You can find several videos which will help a lot in understanding AP more . Background replacement details are also available. You may not be needing LAB mode at present because it can easily mess up the image . All the videos will be using the default RGB mode unless it is specifically mentioned.

In the 2nd image you have posted, tree mask needs further refinement for an improved blending. Since there is good contrast between the tree and sky in original image, it will not be difficult to achieve this, once you watch a few videos on background separation.




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I have just tried with your uploaded image. The method may appear a bit complex. There are other ways also, of doing this. The basic steps are explained below.

Duplicated tree image. Selected first layer, filters>apply image>use current layer>click equations> DR=SB, DG=SB. This will replace the red and green channel with blue channel. I selected blue channel because it gives max contrast for this image. Now there is a B&W image of the tree. This is the last layer renamed as mask before blur. This is blurred at 0.3 pixels and a layer is made with name mask blur. CNTR+ALT+Left click on the layer mask blur will load a selection and marching ants can be seen. Move cursor to the tree layer and select it. Then click on the mask icon. A mask will be created with the selection. This mask has to be inverted using the channels tab at the bottom. A curves adjustment layer is put above the mask and alpha channel is selected in the curves adjustment. Now the curves adjustment will affect the mask and not the tree layer. See the image preview to observe the effect.

My above description is not perfect and could be confusing but it conveys a way to do it. You can follow some of the youtube videos which explains things better. I have used a slightly complex way to achieve the same result.

Hops this helps !



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