findcontours mystery unsupported format

edit

I have read the post on the issue and am still at a loss.

I have a processing pipeline color image > greyscale > laplacian

    **depth = cv2.CV_16S
    kernel_size = 3
    Lap_Img = cv2.Laplacian(gray,depth,ksize=kernel_size)**

Then dilation 10X erosion 10X

    **dilation = cv2.dilate(Lap_Img, kernel, iterations=10)   # Dilate X10
    erosion = cv2.erode(dilation, kernel, iterations=10)    # Erode  X10**

Now I do a binary threshold:

    **ret, th1 = cv2.threshold(erosion, Thresh, 255, cv2.THRESH_BINARY)**

and how I want to find the large contours and create binary mask ret, th1 = cv2.threshold(erosion, Thresh, 255, cv2.THRESH_BINARY)

An here is where get the error Unsupported format or combination of formats) [Start]FindContours supports only CV_8UC1 images when mode != CV_RETR_FLOODFILL otherwise supports CV_32SC1 images only in function 'cvStartFindContours_Impl'

I'm at a loss here, please advise.

Thanks