Masks / Layers
Table of Contents
Masks
Masks are a way of selectively editing a photo. For example, you could apply a black and white filter to an image, but use a mask so that you leave an individual object in the image in color. Masks can be used in conjunction with almost everything in the filters menu, and can be applied regardless as to whether or not you have layers turned on. To use masks, first go to the filter you want to apply, adjust the settings like you would if you were to apply it to the whole image, then press on the brush icon button rather than the check mark. This will bring up the masking controls.
Masking Tools
| Icon | Tool | Description |
|---|---|---|
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Scroll/Zoom | When in this mode you can position and zoom the image to where you want for using the other tools. You can still use two fingers to zoom when using brushes, but if you're not careful you may leave some stray brush marks, therefore this mode is safer to use. |
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Brush | The brush tool lets you use your finger to paint on changes to the image. You can set the size, softness, and opacity of the brush (I would recommend using a soft, low opacity brush most of the time). The brush will scale as you zoom in and out of the image letting you make large changes when zoomed out, and giving you finer control when zoomed in. |
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Filters | Works identically to the brush tool, except it will remove the mask. |  |
Gradients | You can use the gradient tool in combination with curves/levels to mimic a graduated ND filter. A few variants on both circular and linear gradients are possible. 2 control points will appear on the screen which you can move to set the gradient. |
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Color Range | This tool lets you choose a color and apply the mask to only that color (and similar colors). Useful for affecting objects with a fairly uniform color, such as making a blue sky bluer. You select the color by moving the loupe over the color you want, and then changing the slider to set the range of colors to mask. |
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Opacity | The opacity tool will simply set the opacity of the entire mask. |
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Vignette | The Vignette tool works just like the vignette filter, except it allows you to use the shape of the vignette on other filters. You could use it to blur the edges, or to desaturate the edges of a picture, for example. |
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Invert | Inverts the mask. |
Layers
Like many more advanced image editing applications, Filterstorm allows you to use layers to edit. However, the way layers are managed is a bit unique to Filterstorm.
Each Layer is composed of an image, a mask which describes which parts of the image are opaque, and which parts are transparent, an overall opacity, and is blended to the layers below it according to a specific blend mode. In the layers view, each layer will show you a preview of its image, and mask. The color black in the mask preview shows you where the layer is opaque, and the color white shows you where the layer is transparent. The opacity and blend modes can be set from under the settings button on the top left of each layer view.
If you apply a filter using a mask, a new layer will automatically be created containing that edit, and the mask. If you wish to apply a second filter using the same mask, you can tap on the layer preview image labelled "Edit Image" to bring up the filters menu.
If you tap the "+" button on top of the layers view, a new opaque layer will be made the top layer, containing the flattened contents of all the existing layers. If you tap the icon with a "+" inside a camera, an image picker will come up allowing you to choose an image from the iOS photos app to make the contents of the new layer. That image can then be positioned and rotated to fill the layer as you see fit. You can also duplicate or delete by tapping on the settings button on the top right of each layer preview.
Filterstorm currently limits you to 5 layers for memory and performance reasons. If you perform an action that will create a 6th layer, the bottom 2 layers will be merged before that action occurs. The layer limit is subject to change as iOS hardware and software improves.