Smart scaling with Content-Aware Scale

New to Photoshop CS4 is its Content-Aware Scale tool which allows you to transform an image in a way that you’ve never been able to do before in Photoshop. The technology itself has been around for some time and you may have been familiar with the website rsizr.com which offers content aware scaling as an online service. However, the feature is now built into Photoshop making it a readily accessible tool for images large and small.

In this post, I’ll explain how to use content aware scaling and how to protect areas of your image from being distorted in the process.



Step 1
To see the tool at work open an image in Photoshop CS4 (this feature is not in other versions of Photoshop), double-click the background layer to turn it into a regular layer and choose Edit > Content-Aware Scale.



Step 2
Notice the sizing handles on the image. Drag from one side inwards and watch what happens as you do so. You’ll find that the image shrinks in size, but most of the information in the image is still there - the image is made narrower but key elements in it are not squashed up.

If your image includes people, click the person indicator on the toolbar so that it is not pressed in - when the indicator is flush with the toolbar the option is selected. This protects people by recognizing skin tones and ensuring that they are not distorted by the effect.



Step 3
You can also protect elements in the image using an alpha channel mask. This technique is handy if you have areas of the image that you want to retain at the expense of other areas and it can also be used to protect people in the image.

Make a rough selection around the area that you do not want to be affected by the scale effect. A good tool to use is the Lasso tool - select an area and hold the Shift key to make a second selection over another area, if necessary.

Choose Select > Save Selection, type a name for the selection, such as detail mask, make sure that the Channel is set to New and the operation is set to New Channel and click Ok. Press Ctrl + D (Command + D on the Mac) to deselect your selection.



Step 4
Now choose Edit > Content-Aware Scale and from the Protect dropdown list on the toolbar, select the mask you just created. Scale the image and notice that the masked areas are protected from being damaged as the image shrinks in size.

Content-Aware Scaling is a handy way to change the aspect ratio of an image. For example, you can turn a landscape image into a square image and close up the space between people in a photo if they are a long way apart. It also works in reverse and you can use it to make an image larger. You may need to do some work with the clone tool to repair small areas of the image damaged as the result of the scaling but typically the tool does a very good job.

If you don't have Photoshop CS4 then head, image in hand, over to rsizr.com and give the online tool a try. Here is an earlier post I wrote on the Rsizr tool.

Photoshop - keep a log of everything you've done

How many times have you created a neat effect on an image using Photoshop and then wanted to duplicate the effect on another image? The problem is that unless you’ve taken notes about what you've done, it is often difficult if not impossible to remember exactly the steps you took to get the final image.

While Photoshop has a History feature this is of limited use. One problem is that, by default, Photoshop only stores 20 history states so, if you've performed a lot of steps they may not all appear in the list. The second problem is that, even if you have configured Photoshop to store a large number of history states, all you see in the History panel is a brief description of what you did to the image such as Gaussian Blur, Apply Image, Blending Change and you don't see the actual settings used.


The History panel in Photoshop lists the basics of what you've done but not the detail.

Here are some ways to improve on the basics and keep a log of your work:


Step 1
Before you start work on an image choose Edit > Preferences > General and select the History Log checkbox. You can select to save log items to the image Metadata, to a separate text file or to both. If you select either Text file or Both you’ll be prompted to enter a file name and a location to save the file to. Do this and click Save.

From the Edit Log Items dropdown list select Detailed. Sessions records only the time you spend working on a file, Concise records the Sessions information and the detail from the History palette and Detailed records the detail about the changes – it's Detail you need.


Step 2
Now, when you work on an image, the detail is stored in the text file, the Metadata or both, depending on the setting you chose.

If you chose to store the data in a text file you can later open the text file with a word processor or a text editor such as Notepad on the PC.

If you chose to record the history in the image metadata choose File > File Info > History and you can read details of the edits you made to the image in the dialog. Use this information to perform the same steps on another image


Tip
To configure Photoshop to store more than the default 20 history states, choose Edit > Preferences > Performance and set the History States value to a higher number. You should note that this History information is available in the History palette and only while the image is still open – it is lost when the image is closed – unlike the Log data which is stored permanently.

Rsizr - Image scaling on steroids

While Photoshop, Lightroom and Photoshop Elements can resize images for you, only Photoshop CS4 supports content aware scaling. I'll talk about this new feature in Photoshop in another post but if you're interested in playing with content aware scaling and you don't own Photoshop CS4, check out Rsizr.com

Rsizr resizes images by removing the unnecessary content from them or by stretching neutral areas of the image to make the picture bigger. It’s worth a visit just to see it at work.


Start by uploading an image that you want to resize. This should be a JPEG, .PNG or GIF file with a height and width of less than 2,880 pixels – in practice, so you can see what's going on quickly, upload an image sized smaller than this.

Once the image appears in the dialog you will see tabs with buttons for various functions including the File Function tab, View functions, Resize and Retarget functions.


The program uses a seam carving technique to remove portions of the image. To get started drag the horizontal slider in the top of the window in to the size you want the image to be resized to. Click the Retarget button and watch as the seams are created (they're the red marks you can see in the image) and the file shrinks in size.


Once the seams have been created, you will see a set of sizing handles around the image which you can use to resize the image either to make it wider or narrower.


You can protect areas of the image or mark them for deletion by clicking the Preserve or Remove indicators on the retarget functions tab and paint over the area to keep or remove.


You might do this, for example, if you see some distortion in the resizing process and want to protect key portions of the image.

The rescale and crop tools are similar to what you're used to using in your photo editing software - it's the retarget option which is unique.

If you're interested in learning more about seam carving technology, visit: www.seamcarving.com to see a video describing it.

Stop Press! There is a cool plug-in available for the Gimp which brings content aware scaling/seam carving to the Gimp. For more information and to get the download, check here: http://liquidrescale.wikidot.com/ and note that the Gimp version is called Liquid Rescale! Just in case you thought there weren't enough ways to refer to the same thing.

How to merge or combine paths in Photoshop

One of the most difficult things to work out how to do in Photoshop if you work with paths is to know how to merge or combine two paths into one.

Say, for example, you have a working path and a second path and you want the two to appear as one path so you can save it or work with it as a single entity. It sounds easy but merging or combining paths is anything but.

The solution is this:


First, convert the working path to a regular path by double-clicking on its name and click Ok. In this example, I have Path1 and Path2.

Click to select Path2 in the Paths palette. Select the Path Selection Tool and click on the path so it is selected (you will see its nodes appear). Press Ctrl + C (Command + C on the Mac), to copy it to the clipboard.

Click on Path1 in the paths palette so that it is now selected and press Ctrl + V (Command + V on the Mac) to paste the copied path into this path. You now have a single path that contains both your paths and you're almost done.



Check the Tool Options bar as it contains the tools you need to work with the two paths. You can add the shape, subtract the shape, take the intersection of the two shapes or exclude overlapping shape areas – click each and check the diagram in the path thumbnail to see the result to determine which one you want. Select the desired option and click the Combine button and the paths will be permanently joined.



Here is an example where one path is contained inside a second path. You can choose from a number of options for combining the paths depending on whether you want the doughnut, the hole or something different!

Photoshop: Panorama with a twist

Panoramas don’t have to perfectly or neatly aligned. If you’re looking for a fun way to create a panorama in Photoshop the best way to achieve the effect is to throw away the rule book on how to capture and assemble a panorama and try something a little different. In this article, I’ll show you how to capture the images and create a stylish panorama which is anything but perfect.

Traditionally, you capture images for a panorama using a tripod and taking care to ensure that all the shots overlap and that the camera settings do not change from one image to the next. For my panorama I ignored the rules and captured my images with a hand held camera, ignoring changes in the camera settings and continually varying the camera angle from one image to the next. However, you will still need to have plenty of overlap from one image to the next as the panorama tool needs this to assemble the final image for you.


Download the panorama sequence onto your computer and open all the images in Photoshop. Choose File > Automate > Photomerge to open the Photomerge or panorama tool. Select the Cylindrical, Auto or Perspective options – each renders a different result and disable the 'Blend images together' checkbox – this is important as you don't want the images blended at all. Click Add Open Files to select the open files as those to create the panorama from. Click Ok and wait as Photoshop assembles a panorama from the images that you have selected – this may take some time.


When the process is complete you will have a panorama that is bent in interesting directions with the images making up the scene overlaid over each other in a haphazard arrangement.


To add the final touches to the project, start by adding a new layer behind the panorama images by choosing File > New > Layer and click Ok. Drag it to the bottom of the layer stack and fill it with your chosen background colour. To get a colour that works with your image, sample one from the image itself using the eyedropper.

To adjust the panorama’s contrast and brightness add a new adjustment layer by clicking on the topmost layer and choose Layer > New Adjustment Layer > Curves. Drag on the curve until you have a result you like. This adjustment layer will affect all the layers in the image. If you need to adjust only one layer, select it and choose Image > Adjustments and select the adjustment to make – doing it this way ensures the adjustment affects only the selected layer.


Select one of the layers in the image and click the Add Layer Style icon at the foot of the layer palette. Select Stroke and set the stroke Color to White and add a large enough sized stroke that you can see it clearly. Set the Position to Inside and click Ok.


In the Layers palette, right-click on the Layer Style that you just created and choose Copy Layer Style. Select all the panorama layers in the image right-click and choose Paste Layer Style to apply the stroke outline to all the layers.


For additional interest, click some of the layers in the image and either drag them a little out of position or drag their layer to a different position so they are more or less visible. You can also add a drop shadow to the layers the same way you applied the stroke outline.