Questions & Queries Corner 2011 - Page 102

The .PSD (Photoshop Document), Photoshop's native format, stores an image with support for most imaging options available in Photoshop. These include layers with masks, color spaces, ICC profiles, transparency, text, alpha channels and spot colors, clipping paths, and duotone settings. This is in contrast to many other file formats (e.g. .EPS or .GIF) that restrict content to provide streamlined, predictable functionality. PSD format is limited to a maximum height and width of 30,000 pixels. .PSB (Photoshop Big) format, also known as "large document format" within Photoshop, is the extension of PSD format to images up to 300,000 pixels in width or height. That limit was apparently chosen somewhat arbitrarily by Adobe, not based on computer arithmetic constraints (it is not close to a significant power of two, as is 30,000) but for ease of software testing. PSD and PSB formats are documented.^[10]

Photoshop's popularity means that the .PSD format is widely used, and it is supported to some extent by most competing software. The .PSD file format can be exported to and from Adobe Illustrator,Adobe Premiere Pro, and After Effects, to make professional standard DVDs and provide non-linear editing and special effects services, such as backgrounds, textures, and so on, for television, film, and the Web. Photoshop's primary strength is as a pixel-based image editor, unlike vector-based image editors. However, Photoshop also enables the creation, incorporation, and manipulation of vector graphics through its Paths, Pen tools, Shape tools, Shape Layers, Type tools, Import command, and Smart object functions. Utilization of these tools and commands provides convenience when it is desirable to combine pixel-based and vector-based images in one Photoshop document because it can eliminate the necessity to visit more than one software program and transfer files between them. However, for the initial creation of very complex vector graphics that contain numerous shapes and numerous colors, it is much easier to use a software that was created primarily for that purpose, such as Adobe Illustrator or CorelDraw. If it is then necessary to import the complex vector object into Photoshop, it is possible to import it into Photoshop as a Smart Object. When the Smart Object is double-clicked on Photoshop's layers palette, it is opened in its original software such as Adobe Illustrator where changes can be made, then after saving it, the Smart Object will be automatically updated in Photoshop.