Update engine.py (#2187)

adding slight clarification to evaluation logic area, regarding images

references/detection/engine.py

@@ -81,13 +81,13 @@ def evaluate(model, data_loader, device):
     iou_types = _get_iou_types(model)
     coco_evaluator = CocoEvaluator(coco, iou_types)
 
-    for image, targets in metric_logger.log_every(data_loader, 100, header):
-        image = list(img.to(device) for img in image)
+    for images, targets in metric_logger.log_every(data_loader, 100, header):
+        images = list(img.to(device) for img in images)
         targets = [{k: v.to(device) for k, v in t.items()} for t in targets]
 
         torch.cuda.synchronize()
         model_time = time.time()
-        outputs = model(image)
+        outputs = model(images)
 
         outputs = [{k: v.to(cpu_device) for k, v in t.items()} for t in outputs]
         model_time = time.time() - model_time