Image rectifier usage

  • With our Image Rectifier you can straighten diagonally taken photos, e.g. of house walls or other objects, so that all sides are parallel to the edges of the image.

    1 General

    The tool was programmed in 2012 to facilitate the workflow when creating textures. There are some bugs and operating weaknesses, but they can be easily avoided - these are mentioned in the text. We would like to make it available to you anyway, as it might also make the work easier for some of you. We use the tool ourselves permanently with every texture we create.

    2 Setup

    The tool is attached and does not need to be installed. It is a good idea to unzip the tool into a separate folder near the personal texture editing folder. It is important that the two DLLs that come with the tool remain in the same folder.

    3 Usage

    This is what the tool looks like after starting it, if the initialization worked:

    With the "Load" button in the upper left corner or optionally by dragging and dropping a single file in BMP, JPG or PNG format, a file is displayed for editing:

    Then the four circles in the corners of the blue grid are drawn to the corner of the - in this case - house texture. Holding the Shift key supports fine motor skills.

    If the house front is also bent due to a wide-angle lens, the additional four circles in the middle of the sides of the grid are drawn a little bit outwards or inwards. In the example this is not necessary.

    If the front is taken from a very large angle and thus is very slanted, the center of the grid must be moved with the slider at the center top - in such a way that the centers of the sides of the grid are then on the actual center of the house front. This is also not necessary in the example.

    Once everything is set, the preview can be used. To do this, press the "Render" button. Attention, the preview is distorted because it simply fills the image. The result is not distorted! As soon as the mouse is moved again, the preview is finished and the file can be edited further. Even in this state, the preview is sufficient to detect missing fine adjustment, because what is cut off or not straightened or now bent can be detected even in the distorted state.

    If the result is satisfactory, it can either be exported as BMP by clicking the "Save" button, or - as we use it - exported to the clipboard with "Render and Copy to Clipboard" and used from there, for example when arranging a final house texture:

    Attention: The program is not responding during the export. Windows usually notices this, but the program does not need to be closed, it is only busy for 30-120 seconds, depending on the texture size.