PhotoKit Color 2.0: Saving Images

Once you learn how to use PhotoKit Color 2.0, saving your images becomes a very important consideration. If you open up an image from a basic, compact digital camera, the odds are that the file format is JPEG, which is a common file format for digital cameras. The JPEG format creates much smaller files than other formats, but does so at the expense of image degradation, and hence is not ideal for saving images that have been edited.

JPEGs compress the color information while trying to preserve most of the luminance information, because our eyes are much more sensitive to small variations in luminance than to small variations in color. This compression process is called "lossy" because some information in an image is 'lost'. While the initial compression you get from a digital camera is not severe, opening a JPEG in Adobe Photoshop and re-saving as a JPEG further degrades the image. Repeated opening, modification and re-saving as JPEG should therefore be avoided.

Saving a layered image
When you run a PhotoKit Color 2.0 effect on an image, the result is a layer sitting on top of the original image. This is extremely useful for image corrections and manipulations. But adding layers not only adds to the size of the saved file, it also limits your choice of file formats when saving.

If you attempt to save an image that has a PhotoKit Color layer on it, you cannot save as a JPEG because JPEGs do not allow layers. So, you can either flatten the image and allow Photoshop to re-compress the image as a JPEG (bearing in mind that doing so will introduce further image degradation) or save the image using a different file format.

Because Photoshop tries to prevent you from accidentally saving over a file, Photoshop adds the word "copy" when you try to save an image with a layer in the file as a JPEG. This prevents you from accidentally over-writing your original file. This is a good thing, even it is occasionally annoying.

Saving a copy of the original
It is possible to remove the word “copy” from the filename and save a JPEG that overwrites your original, but we strongly recommend that you refrain from doing so unless you absolutely need the smallest file size possible.

If, for any reason you do save out the file as a JPEG, be sure to keep the word "copy" in the file name or add an addendum to the name such as ADJ to avoid saving over the original JPEG.

Preserve all PhotoKit layers using the PSD format
Ideally, you should save your image with all the PhotoKit Color layers intact. This allows you to come back to the image and make additional changes without having to worry about problems you may have with JPEG artifacts from repeated saves while preserving your layers for later editing.

Photoshop's native file format is .PSD (Photoshop). With a PSD file, anything you create in a Photoshop file can be saved including image layers, adjustment layers and type layers. The PSD file format includes a level of compression using a completely lossless scheme so you can be assured that you'll never suffer recompression artifacts.

Preserve all PhotoKit layers using the TIFF format
While many applications can open PSD files, there is another format that has even wider acceptance called TIFF. It should be noted however that while Photoshop can indeed save layered files in the TIFF file format, layered TIFFs can only be read by Photoshop at this time. TIFF files, therefore do not have the same interchangeability that PSDs have. However, TIFFs do offer additional lossless compression schemes that can make the saved file size smaller.

A TIFF can use LZW, ZIP and even JPEG compression. Note that the JPEG compression inside a TIFF is still lossy. If you select ZIP compression, this is the most efficient type of TIFF compression.

Summary
To recap, running a PhotoKit Color 2.0 effect on a file adds a layer or layer set containing several layers. Not all file formats can save layers so you need to choose whether or not to save the layers or flatten. If you do flatten, consider adding a file name addition to avoid saving over your original file. If you need to save in a JPEG file format, understand that it will compress your file in a lossy manner. You should avoid re-saving over and over as a JPEG.

Both PSD and TIFF file formats can save layers. TIFF has a ZIP compression which is the most efficient lossless compression scheme.