Macromedia yesterday filed a series of patent-infringement counter-claims against Adobe.

The company is accusing Adobe of infringing three Macromedia patents. One concerns blended elements and automatic element-re-blending in Adobe Illustrator.

The other two patents relate to the visual display and editing of sound waveforms in Adobe Premiere.

Defence The action was a response to Adobe’s lawsuit against Macromedia, citing the violation of two Adobe patents – a claim Macromedia rejects as "lacking merit".

Adobe is accusing Macromedia of violating its patent for tabbed palettes. An amendment to the suit added an additional claim of patent infringement concerning the image-rendering features of Macromedia Dreamweaver and Flash.

Kevin Lynch, president of products for Macromedia, said: "Macromedia has no choice but to vigorously defend itself against the Adobe lawsuit."