The cpdf_import_jpeg() function opens an image stored in the file with the name file_name. The format of the image has to be jpeg. The image is placed on the current page at position (x-coor, y-coor). The image is rotated by angle degrees. gsave should be non-zero to allow this function to operate correctly.
可选参数 mode 决定单元的长度。如果为 0 或被省略则使用该页指定的默认单元。否则坐标忽略当前单元而使用 postscript 的点来度量。
See also cpdf_place_inline_image().