Photoshop: Blend raster shapes uniformly into eachother

Question

I have a raster file (.tiff format) such as the sample below and I was wondering how I could do a blend between the round lightgreen shape and the darkgreen shape in Photoshop (without affecting the other features -> blueish shape and beige shape)?

The final result will be a landuse layer of a map and will be draped over terrain information like this

The border of the round lightgreen shape isn't clear and therefore should slowly blend into the darkgreen shape. How could I achieve this effect in Photoshop? I tried using the Smudge Tool, this partly works, but a uniform blend would be best.

EDIT

I tried to use ACEkin's answer and separated each shape to a different layer by using the Magic Wand Tool, selecting the shape and then right click "Layer by Copy". Then in the layer panel, I clicked on the separated layer with the lightgreen round shape and selected the shape with the magic wand tool. I did a right click and feathered the shape by 5 pixels and then again right clicked and "Layer by Cut". I then turned of the created layer and have the ghost area as you described. My image now looks like this.

However I am not sure how to proceed next. I don't really understand the step with the clone tool.

In the end I am looking for a result to achieve a gradual blend between the lightgreen and the darkgreen shapes, the river etc. doesn't need to have a blend as its borders are clear.

Here you can find the .psd file for my project.

Answer 1

Here is what I will suggest:

1. Pick up the marquee tool and target the roundish shape you want to blend with the dark green large background, that is click on that layer on the layer stack
2. Ctrl-Click on the thumbnail of the layer which will select the image
3. While the selection is active, inside the selection right click and select from the menu "Feather" and depending on the image size pick a number, that will be the number of pixels will be feathered going to nothing. Try a 10 pixel feather and see how it looks.

UPDATE

I understand that you are dealing with a single layer rather than multiple layers with blending issues.

You need to separate each shape to its own layer, using a copy of the original image follow the steps below.

1. Using the Quick Select or Magic Wand tool select the blue river
2. Right-Click inside the selection and click on "Feather" and feather it by a few pixels
3. Again Right-Click inside the selection and choose "Layer via Cut". This will create a new layer of the river. Now turn off this new layer and you will see a ghost edge of the river
4. Using the clone tool cover the ghost area and the void left from the cut portion. The remaining old layer will have the background and the roundish shape.
5. Separate the roundish shape from the background using the steps 1-4 and clean the solid background

Now the shapes should be blending with smoother edges. If they are too fuzzy around the edges, using a copy of the original repeat the steps but with a smaller feather amount.

UPDATE on clone tool:

1. The clone stamp looks like a rubber stamp on the toolbar. Click to pick it up
2. You need to select a source to use which will be applied to the destination. To do that, Alt-Click on an area you consider to be a good source, most likely the background area in both cases
3. Now, let go of the Alt key and click on where the river was and you will see that the tool is taking content from the source and applying to where you click, destination. Repeat that until you cover the cut areas. Be aware that the tool may clone aligned with the source, in other words after the first click, the source and destination points will move in tandem. This may create potential problems as you get closer to some other content area. In that case, pick another source and continue.

Is it possible that you are biting more than you can chew? ;-)

Answer 2

ACEkin's method is the correct way, but since you've already done it an incorrect way and given your skill level it might just be easier to airbrush:

Select the Brush tool (B), select the circles color Alt+LMB on the color, increase the brush size A LOT --- like 200 is probably good if you posted actual size, lower the Brush Hardness to 0, paint with the center of the brush somewhere in the yellow area so only the outer area overlaps with the dark green. Adjust your brush size to be bigger still and repeat until you get it how you like it.

Tip: Use the Select → Color Range on the River then Copy/Paste it to a new layer:

1. Ctrl/Cmd+C
2. Shift+Ctrl/Cmd+N
3. Ctrl/Cmd+V

Then do the aforementioned airbrushing on another New Layer BETWEEN the River and the original background.