Correct "NoImages" in debug pdf file
Correct "NoImages" in debug pdf file

Issues:
  Debug information for "NoImages" just be binary image,
  it don't show up the result of photo_mask_pix to developer

Fix:
  Substract binary image to photo_mask_pix, the result
  are "NoImages" binary pix

stweil/tesseract,stweil/tesseract,tesseract-ocr/tesseract,amitdo/tesseract,stweil/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,UB-Mannheim/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,amitdo/tesseract,amitdo/tesseract,stweil/tesseract,UB-Mannheim/tesseract,UB-Mannheim/tesseract,tesseract-ocr/tesseract,stweil/tesseract,amitdo/tesseract,amitdo/tesseract