Hi i have this layer :
And this layer :
And what i want to do is add those black lines to the red layer but i dont want the white parts , how can i do this ?
When you put the pavement image in a new layer above the red background, I would try to do some smoothing first to make the colors more consistent. Additionally, your image is of very bad quality and you should try to use a better image of a similar pavement.
When you think the quality of your image is OK, convert it into gray or black/white by thresholding and you get something like this:
Now got to the Layer window and choose negative multiply as mode and adjust the level of the mixture as you like it. Your result will something like this
which is hopefully the result you wanted. Btw, when you want the edges to be black, you just have to invert the edge image: