The SGI file format stores data in the SGI format. Converting to HEIC produces a image file that applies H.265 (HEVC) intra-frame compression achieving roughly twice the efficiency of JPEG at equal visual quality, used natively by Apple devices. This renders each page as a raster image, making the content viewable without a document reader. Each page is rendered at the specified DPI and saved as a separate image; text in the output is no longer selectable. This makes HEIC the practical choice when the destination system requires it or when the original format is not supported by the target application. 1converter runs this conversion on the server: your file is uploaded encrypted over HTTPS, converted using trusted open-source libraries, and the output is held for 24 hours before automatic deletion.