CMID is a dataset specialised for Copy-Move forgeries. It contains automatically generated tampered ID documents. At the time of writing, a base of 304 documents were used to produce 893 tampered images. Those number might evolve over time but the structure will stay the same. There will be one tampering only per images, and no post-processing was applied. The following section will give a brief overview of the dataset.

Structure

The dataset is decomposed into three main folders. The ref, gt and tampered folders. The ref folder contains the pristine images used to produce the forgeries, the gt folder contains the ground truth binary mask and the tampered folder contains the tampered images.

Ref folder

Inside the ref folder, images will be named following this convention :

NAME_X

With NAME being an ID document identifier such as BEL_P_N for the national Belgian passport. And X a numerical index (starting from 0) representing a unique photo of one ID document. One ID document can be present multiple times in the dataset. For example, if there were 18 pictures of the national Belgian passport. Then, the 5^th image of this document will be named :

BEL_P_N_4

Ground truth and tampered folders

Inside the tampered folder, images will be named following this convention :

Y_NAME_X

With NAME_X the name of the reference image used. And Y a numerical index (starting from 0) representing a unique tampering of image NAME_X.

Inside the gt folder, the binary mask will have the same name as the tampered images. So for the tampered image tampered/BEL_P_N_2_1.png, the corresponding binary mask will be found at gt/BEL_P_N_2_1.png.

Ground truth format

The ground truth masks will be provided as RGB images to allow source/target identification.

The localisation of the source element will be in the green channel and the localisation of the target will be in the red channel. The blue channel will always be empty (i.e. filled with zeros).

Example of tampering

In the above example, we can see the tampered image on the left and the ground truth mask on the right. The mask indicates that the character at the location of the green patch has been copied and move to the red patch location.