IntroductionTiffExtract is a simple program that uses QISLIB to open a GDSII file and extract the data in a small window and convert it into a monochrome bitmap. This is a useful function for inspection equipment -- the bitmaps are often used for defect detection. ![]() The purpose of TiffExtract is primarily educational - it is intended to help a programmer who plans to use QISLIB get up to speed quickly. We provide a complete source project for TiffExtract and a binary that a programmer can use to excercise QISLIB. For high performance applications a one would prefer NexgenRIP which has a 2nd generation multi-threaded rasterizer built in. |
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Opening a GDSII FileIn order to open a GDSII and process one or more layers the client (TiffExtract) program needs to:
Selecting the Window and Producing a BitmapOnce this is done the next step would be to:
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The flow chart below shows the important function calls that must be made prior to opening the GDSII file. ![]() Once the GDSII file is opened then the correct structure should be opened and the layer(s) of interest set to ON. ![]() Now we can define a window of interest and instruct QISLIB to rasterize that window into a TIFF file and write the file to disk. These two steps can be put into a loop and hundreds or thousands of windows extracted. ![]() When we are done extracting windows, the calling application should close QISLIB. This releases the memory (which could be quite a lot!) and also releases the license. ![]() |