his brother John, an Industrial Light & Magic employee, who recommended that Thomas turn it into a full-fledged image editing program. Thomas took a six-month break from his studies in 1988 to collaborate with his brother on the program. Thomas renamed the program ImagePro, but the name was already taken. Later that year, Thomas renamed his program Photoshop and worked out a short-term deal with scanner manufacturer Barneyscan to distribute copies of the program with a slide scanner; a "total of about 200 copies of Photoshop were shipped" this way. During this time, John traveled to Silicon Valley and gave a demonstration of the program to engineers at Apple Computer and Russell Brown, art director at Adobe. Both showings were successful, and Adobe decided to purchase the license to distribute in September 1988. While John worked on plug-ins in California, Thomas remained in Ann Arbor writing code. Photoshop 1.0 was released on February 19, 1990, for Macintosh exclusively. The Barneyscan version included advanced color editing features that were stripped from the first Adobe shipped version. The handling of color slowly improved with each release from Adobe and Photoshop quickly became the industry standard in digital color editing. At the time Photoshop 1.0 was released, digital retouching on dedicated high-end systems (such as the Scitex) cost around $300 an hour for basic photo retouching. The list price of Photoshop 1.0 for Macintosh in 1990 was $895. Photoshop was initially only available on Macintosh. In 1993, Adobe chief architect Seetharaman Narayanan ported Photoshop to Microsoft Windows. The Windows port led to Photoshop reaching a wider mass market audience as Microsoft's global reach expanded within the next few years. On March 31, 1995, Adobe purchased the rights for Photoshop from Thomas and John Knoll for $34.5 million so Adobe would no longer need to pay a royalty for each copy sold. File format Photoshop files have default file extension as .PSD, which stands for "Photoshop Document". A PSD file stores an image with support for all features of Photoshop; these include layers with masks, transparency, text, alpha channels and spot colors, clipping paths, and duotone settings. This is in contrast to many other file formats (e.g., .JPG or .GIF) that restrict content to provide streamlined, predictable functionality. A PSD file has a maximum height and width of 30,000 pixels, and a length limit of two gigabytes. From the beginning, Photoshop could save files