CodecPage
 video encoding&cleaning


Logo removal with Xlogo

Xlogo for VirtualDub or VirtualDubMPEG2 is available here (original home, currently down apparently) or here, or a package with all versions and docs and sources, here. We use the 0.4 version, none else.

Note: Contrary to other comments, Xlogo is perfect for transparent logos (we are talking about Xlogo0.4; the 0.5 version found somewhere lost this feature and is hence useless. The AVIsynth versions reportedly have it, but how to set it up it without a live preview?. Results with opaque logos are less useful with any utility, although X-logo is very good in this discipline as well. So I describe the transparent case here.

The original documentation is very complicated and in parts it is quite misleading.
So here is a short guide that works:

We need an image editor; Ulead Photoimpact for example, or if you're looking for a really good free one, PhotoFiltre (free for non commercial use). In VirtualDub, find a black frame or one where the logo is on a black background. Use "save source image to clipboard" and then open it in the image editor with 'insert'.

Cut out the logo, with some pixels of border around it. Take care to write down the origin coordinates of the cut.

Save the cut as a BMP file with coordinates inserted in the file name, for example:


cam2_x_44_y_51_0.bmp

Now use the cutout to make a black version of the logo itself, on a white background. How to do this depends on the image editor. The black should cover all parts of the logo itself, including possible unsharp edges. Best use a color selection tool to mark the black parts of the original logo with a tolerance of 16, then fill this with white, invert the selection and fill this with black. (With PhotoFiltre, use the magic wand, then the "stroke and fill" command from the right click. Be sure to set selection anti aliasing to off!) Save the result as (for example). Attention: adding very small gaps in the logo to the white part here may cause X-logo to crash. Don't overdo. It may even be helpfiul to expand the black areas by one pixel, this avoids edges that could occur especially in colored areas.


cam2_x_44_y_51_2.bmp

Now add the Xlogo filter in VirtualDub and open it. Use the "browse" button to open your logo files: Selecting the ...-0.BMP file automatically opens both, as the 'Black' and 'Interpolate' versions ('White' not needed). Play a little with the settings (use the preview) until the logo is perfectly removed with as little as possible blur imposed on the image itself. 

The feather parameter is apparently not saved by the filter. It also seems to have no effect.
White level and interpolation are used to make the logo really disappear in all cases. Interpolation can
normally almost be omitted.
For blur, small values (1 or 2) will be sufficient. Just press the "Zero" button and enter a 1 at "Bitmap".

Xlogo XXL (HD)

Trying X-logo on HD material reveals that it is limited to a frame size of 800x600, hence pretty useless.

But you can simply change this using VirtualDub's built-in hex editor (you could perhaps also compile the entire filter anew if you use the sources from the above download, but this here is way easier):

Get VirtualDub version 1.10.2 at least, this is necessary for successful HD editing anyway. 

Attention Windows7 users: Windows7 may quietly redirect files saved by programs into their own folder to a special location, due to security paranoia. This behavior can cause major confusion and even loss of data, because the redirection is transparent but inconsistently implemented. It occurs if programs are installed in the Programs folder but are not properly registered to Windows7. It does not occur if a user saves files into the Programs folder (using admin rights).
The best way to deal with this should be creating a folder "PortableApps" in your C: drive and installing all video utilities, portable programs and older software there.




The left pane shows the hexadecimal line numbers and program code, the right pane its according text representation. You may edit in both. Virtualdub's hex editor does not highlight the items found, you have to look for them in the bottom line. Simply overtype the numbers.







Also change the first four occurrences of 58 02 to 70 08, (decimal 2160):

You may also want to search the string “X-Logo (0.4.1)” (Hexadecimal search unchecked) and change it, because this is what Virtualdub displays in its filter list and so you see that you are using the changed version. 





Change this in the right pane of the edit window.
Then save the file. It goes to the "plugins" folder in VirtualDub's program folder . That’s all. The changed Xlogo04-4K.vdf will now allow frame sizes up to  4096x2160 (Cinema 4K format, slightly more than QFHD).

You can use this guide to give X-Logo almost any frame size limit (but don't overdo, as the position sliders in the X-logo windows may become hard to operate with a very large range set).The calculator that comes with Windows can be used to calculate the proper hex values. 

Now if you open VirtualDub's filter list you should see something like this this:

...and the new filter should allow to set its size sliders, e.g., like this:

How to successfully use this with real HD files (h.264 format) is described here (see method 2, in particular).



 



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