The same formula applies, when you want to convert a PDF page to a raster image (this process is called rasterization), because it is the exact same thing except that you will be choosing the output resolution instead of working with the screen or printer resolution. Note that the current display resolution is accessible through HorizontalResolution and VerticalResolution properties of the GdViewer object. When displayed at 150%, resolution is 144 DPI, so the display size will be 1684 x 1191 pixels and so on. When displayed at 100%, the resolution is 96 DPI,so by applying the well-known “ inches = pixels / resolution” formula, the actual pixels needed to display the image will be 1123 x 794 pixels. For instance, let’s take a full A4 page, its height will be 8.27 inches and its width will be 11.69 inches. The physical size of the page won’t change, but depending on the zoom level, the number of pixels used to represent it, will vary. For display, the resolution depends on the rendering zoom level. Only raster images have a resolution, in a PDF document, anything that is text or vector graphic will be rendered at the desired resolution of the output device (screen or printer).
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