GIMP offers various types of filters. To apply one of those filters to multiple layers, you need to group your layers first. We described this process within this article. As it is also important to understand what a filter is and the different types available in GIMP, we made a short list describing them.
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How to GIMP: Applying Filters to All Layers
One of the most effective ways to make alterations to your layers in GIMP is to create Layer Groups. Grouping your layers can be a great organizational tool as it helps smooth some of the inadequacies in GIMP’s overall layer system.
Layer Groups provide a lot more flexibility, and once layers are placed into groups, the groups can be moved around just as you would single layers.
Making a layer group is not a complicated process at all. There are a few shortcut icons at the bottom of the Layer’s palette. You will want to search for the “New Folder” icon, which is the second icon from the left, and then create a new layer group that can be added to the image.
As you can see, Layer groups really are just an organizational tool that lets you maintain various sets of linked layers, considering that grouped layers function just as linked layers. The filter properties applied to the groups affect all the layers in that group.
The great thing about this is that you can apply filters to all the layers within that group, regardless of their hierarchical status. This is a lot more effective than applying each filter to every single layer, particularly if your project consists of many layers.
To apply a filter to all layers, you need to first create the group using the Layer Group image at the top. This links all your selected layers to one single group.
Next, select the Filter Window menu and scroll down to your preferred filter. Then apply the filter to your layer group. Remember to always check on the bottom right of the GIMP application that you have created a Layer Group to make sure the layer group is active.
What’s in a Filter?
A filter is a unique tool designed to take an image or input layer and apply a mathematical algorithm. The result is an image or layer in a modified format. There are a wide collection of GIMP filters available, which users can use for different functions.
The filters include:
These are a set of filters that blur parts of images or their entirety in different ways. If a selection is made, only that part of the image is blurred. But there might be color leakages from the blurred area to other parts of the image.
The noise filter adds noise into the selection or active layer of a project.
Map filters use an object known as a map to alter an image. This means an image is mapped to an object.
The process enables you to develop 3D effects by simply mapping the image to another image that has been embossed. It can also be mapped to a sphere.
Animation filters enable users to optimize and view animations by reducing the image size. These typically work with GIF filters since they serve the same purpose in GIMP.
Web filters are generally used on images meant for websites. For example, the Image Map filter is used to include clickable “hot spots” on an image.
The Semi-Flatten filter is for when you need to simulate semi-transparency in image formats without any alpha channels. The Slice filter provides sensitive images in HTML tables.
The majority of GIMP filters tend to function in such a way that they work on a specific layer by altering its content. However, filters located in the Render group act slightly differently. For one, they can generate patterns out of nothing, and in most cases, they will eliminate anything that was previously on that layer.
Certain render filters create noisy or random patterns, while others create regular or fractal patterns.
The generic filter is a catch-all filter group. It is named so because it contains filters that cannot be placed anywhere else. Some filters found in this subset include the GEGL graph filter, the Distance Map filter, the Convolution Matrix filter (lets you create bespoke filters), the Erode filter, and the Dilate filter.
The artistic filter creates artistic effects, such as oil painting, canvas, cubism, and more. The filters in this group are image-dependent Script-Fu scripts. These scripts can be used to add special effects to certain images and even create decorative borders.
The combine filter, just as its name suggests, combines at least two images into one.
The edge filter searches for borders between varying colors. It can also detect the different contours in objects. Edge filters are typically used to highlight selections and for various artistic purposes.
Light & Shadow
This filter is actually two sets of filters. The light effect filters render various illumination effects on an image. On the other hand, the drop shadow effect filters create different types of shadows.
The distort photo filter is used to change or alter an image in different ways.
Enhance filters are generally used to recompense image imperfections. Things such as noise, interlaced frames, insufficient sharpness, and dust particles are examples of image imperfections.
Applying a filter to all layers within a project can seem like a daunting task, especially when you approach is to apply the filter to every single layer in your project one at a time. Thankfully, you can get around this by using the Layer Groups function, which connects as many layers as you want into a single group. This group can then be altered using different properties.
With a Layer Group, you can add filters across the board, creating a seamless procedure for your Image manipulation project. You just have to make sure that all your Layers are within that layer group.