It has become a common complaint that the United Kingdom Patent Office has been taking a tougher view having regard to the grant of patents relating to computer software-related inventions than the European Patent Office (which in turn proposes stricter criteria than the United States PTO). This situation seems unlikely to change in view of the decision of the Court of Appeal in Fujitsu's Application. The case came to the Court of Appeal as a result of a refusal of the application by the United Kingdom Patent Office. The invention related to a computer program for visualizing the crystal structure that would be obtained by combining various materials which was accomplished by calculations based on information relating to the structure of the materials being combined. It was of particular use in visualizing the crystal structure of semiconductors and superconductors.

Both the European Patent Convention and UK Patent Law preclude the grant of patents for inventions which relate to "computer programs as such". It was agreed that the basic starting point for interpreting the meaning of this prohibition is the European Patent Office Board of Appeal decision in 1987 in Vicom's Application which held that a claim directed to a technical process which is carried out under the control of a program should be allowable since it cannot be regarded as relating to a computer program as such. That decision did, however, draw a distinction between processing to produce a rearranged data array, which was held to be patentable, and a method for "digitally filtering data," which it felt was "an abstract notion not distinguished from a mathematical method so long as it is not specified what physical entity is represented by the data." Although, more recent decisions of the European Patent Office seem to have taken an expansive view of what is patentable in accordance with this decision, the English Court of Appeal was not inclined to do so. It was noted that the decision had indicated that the key to determining patentability was to see whether once one had discounted the fact that a computer program was involved, what was left in the claim related to a technical problem. The Court of Appeal concluded that even though in the Vicom case the production of an image was, as in the present case, the ultimate result of running the program in question, in the Vicom case there was a technical contribution in producing an enhanced image of something that was external to the computer No such enhanced image was produced in the present case in which processing was carried out on an internally produced image. In the Court's view the only advance made in the present case was that a computer program enabled the image to be produced more quickly than it could have been produced without the program and as such what was claimed was not patentable.

The Court went on to indicate that it was irrelevant whether the invention had been claimed as a method or as a computer which had been programmed to carry out a method. One had to look at the claims as a matter of substance not as a matter of form.