Crop tool

The crop tool can be used to crop an image to ‘delete’ or ‘hide’ the image data that falls outside the selected crop area. When you apply a crop with the crop tool, it uses color shading to mask the outer crop area. This provides a useful visual clue when making a crop. You can then use the large Commit or Cancel buttons in the crop Options bar to OK or cancel a crop. Or alternatively you can use the Enter key to OK the crop and the Esc key to cancel (on Macintosh and PC keyboards, these keys should be diagonally positioned, with Esc key at the top left and Enter key at bottom right).

Figure 1 On the left you can see an image with the crop tool active, but no crop applied yet. On the right you can see the image being cropped, before confirming the crop.

Most images will require some kind of crop, in order to focus more attention on the subject. To crop a photo, select the crop tool from the Tools panel. This reveals a crop bounding box that overlays the entire image (Figure 1). You can then drag any of the corner or side handles to adjust the crop. Or, you can click anywhere in the image area and drag to define the area to be cropped. As you crop an image the outer crop appears shielded (see Figure 1 again). As you apply a crop and switch to a modal crop mode the Layers panel temporarily shows a crop preview layer. Don’t worry. It doesn’t mean any layers have been deleted – this is just a temporary preview (see Figure 2). Also, while the crop tool is modal you can hold down Shift key to define a new crop area. If the Delete Cropped Pixels option is checked in the crop tool Options bar, the image will be cropped permanently and the Background layer preserved. If the Delete Cropped Pixels option is unchecked it merely ‘trims’ the image, preserving the original image contents including all the layers information and a previous Background layer will now be promoted to a normal layer. For example, in Figure 2 I show how a Background layer became a Layer 0 layer. Also, as you drag a crop handle you’ll notice how the underlying image moves as you adjust the crop. This makes the Photoshop crop tool behavior more like Lightroom and (in my view) now makes it easier to work with the crop tool.

Figure 2 The Layers panel view on the left shows an image in mid-crop, displaying a crop preview layer. If the crop options are set to delete cropped pixels, an image that starts out with a Background layer will retain the Background layer after being cropped. If the Delete Cropped Pixels option is unchecked, a Background layer will become a Layer 0 layer.

Figure 3 shows the crop tool Options bar in normal mode before applying a crop. Here you can see the crop tool presets menu, which contains the same preset options that appear in the Tool presets panel. This allows you to select a crop setting that applies a crop with the required aspect ratio to crop an image and resizes it to specific image dimensions and a specific pixel resolution setting. This is only useful if you want to crop and resize an image in one go. Most the time you will simply want to crop an image without resizing. So, in these instances you would go to the Crop Aspect Ratio menu shown in Figure 4 and select the Unconstrained option – this allows you to apply a freeform crop. You can also select one of the crop aspect ratio settings from the menu, or enter a new custom aspect ratio by just typing some values into the two field boxes. As you drag on a corner or side handle the crop can be scaled up or down, preserving the crop aspect ratio and you can use the keyboard arrows to nudge the crop bounding box. You can click on the Swap aspect ratio button to swap between a landscape or portrait mode crop (or use the X key). When a crop aspect ratio is in force the crop proportions will remain locked. When resizing a restricted aspect ratio crop box, you can switch between the portrait and landscape orientations by dragging the bounding box from the corner. There is also now a single undo available when working in a modal crop.

Figure 3 The crop tool Options bar.

Figure 4 This view of the crop tool Options bar shows the Crop aspect ratio menu. You can select the default ‘Unconstrained’ option or one of the aspect ratio presets shown here. Or, you can click on Size and Resolution… to open the Crop Image Size and Resolution dialog shown here to create an aspect ratio setting that combines the desired physical image dimensions and pixel resolution. When you click OK, this creates a fixed aspect ratio crop tool preset that also resizes the image to the desired image size and proportions. If you also check the Save as Crop Preset box this saves the settings as a new crop tool preset that will be added to the Tool Presets panel. Or, if you apply a crop and then click on the Add new preset button at the bottom of the Tool Presets panel, this adds a new preset based on the current image size settings.

Overlay options

Once you are in a modal crop state you’ll have a choice of crop guide overlay options (Figure 5). The default ‘Rule of Thirds’ option is shown in use in Figure 1. This applies a 3x3 grid overlay, which can be useful when composing an image. There are other overlay options you can choose. The ‘Grid’ option can be helpful when aligning a crop to straight lines in an image and there are also further ‘Lightroom-like’ options such as Diagonal, Triangle Golden Ratio and Golden Spiral overlay options. You can cycle between these overlay options using the Q key and cycle between different crop overlay orientations using the Shift+O keyboard shortcut.

If you want a crop to match the dimensions and resolution of a document that is already open in Photoshop, click on that document to make it active. Then go to the Crop Aspect Ratio menu and open the Crop Image Size & Resolution dialog shown in Figure 7. You will then need to go to the Source pop-up menu at the top and select ‘Current Image’. This loads the current image dimensions and resolution settings into the boxes below. Click OK to apply this as the new Crop setting. Now select the image you wish to crop and as you drag with the crop tool, this new crop setting will be applied. When you OK the crop, the image size will adjust to match dimensions and resolution of the previously selected image.

Figure 7 This shows how to select ‘Current Image’ as the new crop target setting.

Selection-based cropping

To make a crop base on a selection, all you need to do is select the crop tool (C) and the crop will automatically fit to the selected area. For example, you might want to command/control-click a layer to make a selection based on a single layer and then execute a crop (as described below in Figure 8). You can also make a crop based on an active selection by choosing Image Crop. When you do this the crop tool automatically matches the bounds of any selection. Where a selection has an irregular shape, the crop is made to the outer limits of the selection and the selection retained.

Figure 8 Sometimes it is quicker to make a crop from a selection rather than try to precisely position the crop tool. In the example shown here, if I wanted to make a crop of the box containing the letter D, the quickest solution would be to Command/Control-click on the relevant layer in the Layers panel and select the crop tool (C), or choose Image Crop.

The crop tool in use

To apply a crop, simply drag the crop tool across the image to marquee the area you want to be cropped. You can then refine the position of the crop by directly dragging any of the eight crop handles. Note that if View Snap To Document Bounds is checked, the crop tool will snap to the edge of the document. To avoid this, go to the View menu and uncheck the Document Bounds or general Snap To behavior.

To constrain the proportions of the crop, hold down the Shift key as you drag. You can reposition the crop without altering the crop size by dragging within the crop area. And to rotate the angle of the crop, move the cursor anywhere just slightly outside the crop window. The crop bounding box also has a movable center point. When you click and drag the center point elsewhere, the central axis of rotation is repositioned accordingly, even to a point outside the crop rectangle.

The crop tool cursor icons

When a crop is active, you will see the cursor change appearance as you roll over different parts of the crop bounding box. See Figure 9 below for more details.

Big data

The Photoshop PSD, PDF and TIFF formats all support ‘big data’. This means that if any of the layered image data extends beyond the confines of the canvas boundary, it is still saved as part of the image when you save it, even though it is no longer visible. If you have layers in your image that extend outside the bounds of the canvas, you can expand the canvas to reveal all of the big data by choosing Image Reveal All. Remember though, the big data can only be preserved providing you have saved the image using the PSD, PDF or TIFF formats. Also, when you crop an image that contains a normal, non-flattened background layer and the ‘Delete Cropped Pixels’ box is unchecked, Photoshop automatically converts the background layer to a Layer 0 layer (and preserves all the big data).

Figure 10 The cropped version of this picture contains several layers which when expanded by using the Image Reveal All command shows all the hidden ‘big data’ that extends outside the cropped view. As long as the Delete Cropped Pixels option is left unchecked when you apply the crop this allows you to preserve the pixels that fall outside the selected crop area instead of deleting them.

Trimming an image

The Image Trim... command can be used to crop an image based on pixel color values. Figure 11 shows an example of how the Trim command can be used to crop an image based on transparency.

Figure 11 In this example the Image Trim… command is used to crop the image based on transparency. Photoshop crops all four edges, removing the transparent contents only.