Sharpen Edges in GIMP

This is a quick note of how to apply image sharpening to the “edges” of an image. One reason for creating this post is so that I have somewhere to find the steps involved when I need them. The steps described are for GIMP. It is likely that you can follow a similar process in other image editing software. It might already be part of how sharpening is done in other application.

Sharpening is usually one of the last things you do to an image before saving it.

With the image loaded into GIMP

  1. Create a duplicate layer.
  2. Apply sharpness to the duplicate layer. Feel free to apply more sharpness that you normally would.
  3. Add a layer Mask to the duplicate but select “Grayscale copy of layer” as you do it.
  4. Right click on the layer mask and select “Show Layer Mask”
  5. Go to “Filters” > Edge-Detect > Edge > OK (I haven’t seen any benefit from making any selections from the Edge dialogue)
  6. While viewing the layer mask go to Colors > Curves and pull “darks” down and “lights” up. i.e. increase the contrast. Part of the idea here is to make areas where you don’t need to apply sharpening black. If you do apply sharpening to some of these areas they can get “pixelly”.
  7. If there are areas you don’t want or need to apply sharpening you can paint those areas black on the layer.
  8. Go to Filters > Blur > Gaussian Blur and apply a small amount of blurring to spread the area that the sharpening will be applied over.
  9. Return to the image i.e. no longer show the layer mask. Right click on the layer mask and un-check “Show Layer Mask”.
  10. Adjust the opacity of the duplicate if required to give you the image you want.
  11. Right click on the duplicate and Merge down to a single image.
  12. Save the file. Go to File > Overwrite…

When I have more time I might add some screenshots of this process.

Red Admirals

With the trees and houses around our garden we only seem to get sunshine on part of our Buddleia at a time during this time of year but when we do it can suddenly get busy with butterflies – I guess it isn’t called Butterfly Bush for nothing.

Red Admiral

During one sunny interval yesterday I managed to count 9 Red Admiral on the bush at one time. There were probably others that I didn’t spot.

Red Admiral

The Red Admirals still have to share it with other flying insects like this Bee Hoverfly.

Red Admiral

Some of them looked very fresh with no creases on their wings. This one just has a few on its right wings.

Red Admiral

This one has a rather ragged left wing but it was nowhere near the worst.

Red Admiral

The wings of butterflies are beautiful and to see them on flowers or flitting about in sunlight is great. But I get a bit uncomfortable when looking closely at their heads. It always looks as though there is one dark spot on the eye looking straight at you.

As usual the images are on Flickr and you can see a couple of other photos within the album.

Baildon Moor 24 September 2018

Today was quite pleasant and I made use of the reasonable sunshine to go up onto Baildon Moor. There should be a few passage migrants but I think the wind was in the wrong direction for them.


One of the first things I saw was a Redkite. As usual it drifted effortlessly past and a few seconds later was a dot over towards Shipley Glen.


Quite a few Meadow Pipits were still flitting around as were flocks of Goldfinch still feeding on the seed heads of the thistles in the field near the path leading down to Golcar Farm.


Further round near the tree plantation before the huts were a few small birds flitting between the bushes by the wall into the bracken. They were calling not singing so I wasn’t quite sure whether they were Willow Warblers of Chiffchaffs. Fortunately I managed to get this shot and decide that it was a Chiffchaff. The call didn’t have the extra half syllable on the end so hopefully I will know in future.


Several times I saw a Kestrel hovering over the grassy areas but always too far away to get a photo. But then all of a sudden one was above me. The header images shows it scratching its ear.

Looking West

Over the afternoon clouds kept forming and then disappearing. Some of them let rain fall but only for a few seconds. When the clouds cleared the sky seemed to be criss crossed with vapour trails. At one point it looked as though you could play celestial tic-tac-toe.

Click on an image to see it in the album on flickr. There are a few other photos in the album.

Denso Marston Nature Reserve June 2018

We might well be into September now but I am still catching up with making some of my photos from earlier in the year available. These are from a walk along the river at Denso Marston Nature Reserve.

Juvenile Grey Wagtail

One of the cute things spotted on the walk along the river were several juvenile Grey Wagtails.

Juvenile Wagtail

One of them was calling out to be fed, bobbing about and making a racket. The above image is a link to a video of it babbing and calling.

Adult Grey Wagtail

The adults were busy catching insects and feeding their young.


Blackbirds were both on the ground pushing leaves away to get at insects and also up in the trees eating berries.


There also seemed to be a couple of Jay families around. This one is waiting patiently to be fed


but could raise its crest and demand to be fed when an adult was around.

Grey Heron being attacked by Crow

I think this Crow is trying to convince the Grey Heron to move on and not be near its youngsters,

Grey Heron

It’s amazing that Herons can get quite big fish and other animals down a throat that thin. I think that is looks could kill then that Crow would be smouldering by now.

Crow & Grey Heron

But it looks rather slick and healthy.


On the far side of the river I spotted a female Mandarin Duck with 3 almost fully grown youngsters – nice to see. There was also a family of Goosander. Here is a photo of 2 of the young.

As usual you can click on an image to see it in an album on Flickr. You can see the album here.

Finningley Airshow 1972

Back in the dim and distance days of my youth I was interested in aircraft and used to bike up to a gate next to the taxiway of Binbrook aerodrome and watch English Electric Lightnings. I also went to several airshows at RAF Finningley. I think these photos are from 1972 but I am happy to be told otherwise.

Concorde fly by

Concorde fly by.

Concorde fly by

Concorde had yet to enter service. Scheduled flights did not start until 1976.

Concorde fly by