title: pyautogui / pyscreeze - locate works w/o region parameter, but doesn't work w/ region parameter
body: <p>Using pyautogui, I'm trying to locate an image on screen.</p>
  <p>This finds the image (on primary monitor w/ 2560x1440 resolution), but takes nearly 5 sec:</p>
  <pre><code>icon1 = pyautogui.locateOnScreen('[filepath]\\icon1.png', grayscale=True)
  </code></pre>
  <p>To reduce search time, I provide a region parameter, but this doesn't find the image. It executes in ~0.7 sec</p>
  <pre><code>icon1 = pyautogui.locateOnScreen('[filepath]\\icon1.png', region=(1500,100,950,1100), grayscale=True)
  </code></pre>
  <p>Eliminating the grayscale parameter doesn't change the result - still ~0.7 execution time and image not found:</p>
  <pre><code>icon1 = pyautogui.locateOnScreen('[filepath]\\icon1.png', region=(1500,100,950,1100))
  </code></pre>
  <p>Then I tried setting the region parameter to the entire screen, but image not found and execution time is ~1.5sec, so it's searching (judging by longer execution time w/ larger region), just not finding.</p>
  <pre><code>icon1 = pyautogui.locateOnScreen('[filepath]\\icon1.png', region=(0,0,2559,1439))
  </code></pre>
  <p>Any suggestions on what to try next? Thanks.</p>