image scaling types and dynamic monochrome thresholding

EinkPaper.py

@@ -47,11 +47,12 @@ strList.append(str3)
 
 def initWidgets():
     widgetList = []
-    widgetList.append(widget.TextWidget(cwidth, cheight, 0, 0, 1, 2, str1))
+    widgetList.append(widget.TextWidget(cwidth, cheight, (0, 0), (1, 3), str1))
-    widgetList.append(widget.TextWidget(cwidth, cheight, 1, 0, 2, 1, str2))
+    widgetList.append(widget.TextWidget(cwidth, cheight, (1, 0), (1, 3), str2))
-    #widgetList.append(widget.ImageWidget(cwidth, cheight, 2, 1, 1, 1, "mono", "faces.jpg"))
+    widgetList.append(widget.ImageWidget(cwidth, cheight, (2, 0), (1, 1), "mono", "fill", "img3.jpg"))
-    widgetList.append(widget.ImageWidget(cwidth, cheight, 1, 1, 2, 2, "mono", "calvin.jpg"))
+    widgetList.append(widget.ImageWidget(cwidth, cheight, (2, 1), (1, 1), "mono", "fill", "sun1.jpg"))
-    widgetList.append(widget.ImageWidget(cwidth, cheight, 0, 2, 1, 1, "mono", "img1.jpg"))
+    widgetList.append(widget.ImageWidget(cwidth, cheight, (2, 2), (1, 1), "mono", "fill", "w.jpg"))
+
     return widgetList
 
 def drawWidget(w):

readme.md

@@ -16,7 +16,8 @@ config data --> EinkPaper.py
     e.g.
     widgetList.append(widget.ImageWidget(cwidth, cheight, 1, 1, 2, 2, "mono", "calvin.jpg"))
 
-    Text widget has one 'other argument', it is the string to be displayed on the widget. Image widget has two other args, the type of black and white filter to process the image with, and the location or filename of the image. The two b&w filters are "mono" for monochrome, and "dither" for greyscale dithering.
+    Text widget has one 'other argument', it is the string to be displayed on the widget. Image widget has three other args, the type of black and white filter to process the image with, the type of image size transformation to be performed, and the location or filename of the image. The two b&w filters are "mono" for monochrome, and "dither" for greyscale dithering. Image transforms are "fill", "resize", and "none".
+    The threshold limit for calculating the cutoff for black/white pixels in the monochrome function is calculated in autoThresholdLimit(). The limit is: the lowest pixel value + a factor between 0 and 1 x the pixel value range of the image. The pixel value range is found by performing getextrema() on the image. By default the factor is set to 0.4, or 40%.
 
     Widgets will be drawn on the final canvas in the order they are appended to the widgetList array.
 
@@ -28,7 +29,7 @@ widget.py --> EinkPaper.py
 
 	The program is built for python2.
 	$ python EinkPaper.py
-	If the display package is present, will run with test mode disabled. Will repeatedly update each widget and each iteration will display the latest version on the external display. If the package is missing, will run in test mode, saving the generated canvas images to the working directory.
+	If the display package is present, will run with test mode disabled. Will periodically update each widget and each iteration will display the latest version on the external display. If the package is missing, will run in test mode, saving the generated canvas images to the working directory.
 
 	Or manually enable test mode:
 	$ python EinkPaper.py -t

widget.py

@@ -39,13 +39,13 @@ def putImage(imagepath, maskpath, position, colour):
 class TextWidget():
     #this example widget will have a set size: 3x1 cells (one column)
     #an instance of this widget class can be created and pasted to canvas
-    def __init__(self, cwidth, cheight, x = 0, y = 0, width = 1, height = 1, str = ""):
+    def __init__(self, cwidth, cheight, xy = (0, 0), dim = (1, 1), str = ""):
-        self.width = width
+        self.width = dim[0]
-        self.height = height
+        self.height = dim[1]
-        self.wt = cwidth*width
+        self.wt = cwidth*dim[0]
-        self.ht = cheight*height
+        self.ht = cheight*dim[1]
-        self.cellX = x
+        self.cellX = xy[0]
-        self.cellY = y
+        self.cellY = xy[1]
         self.image_yellow = Image.new('1', (self.wt, self.ht), 255) #255: clear the frame
         self.draw_yellow = ImageDraw.Draw(self.image_yellow)
         self.image_black = Image.new('1', (self.wt, self.ht), 255) #255: clear the frame
@@ -74,18 +74,19 @@ class TextWidget():
 class ImageWidget():
     #this widget displays an image
     #needs to recieve an image file as input. Then resize and convert to monochrome.
-    def __init__(self, cwidth, cheight, x = 0, y = 0, width = 1, height = 1, mode = "mono", img = ""):
+    def __init__(self, cwidth, cheight, xy = (0, 0), dim = (1, 1), bwMode = "mono", scaleMode = "fill", img = ""):
-        self.width = width
+        self.width = dim[0]
-        self.height = height
+        self.height = dim[1]
-        self.wt = cwidth*width
+        self.wt = cwidth*dim[0]
-        self.ht = cheight*height
+        self.ht = cheight*dim[1]
-        self.cellX = x
+        self.cellX = xy[0]
-        self.cellY = y
+        self.cellY = xy[1]
         self.image_yellow = Image.new('1', (self.wt, self.ht), 255) #255: clear the frame
         self.draw_yellow = ImageDraw.Draw(self.image_yellow)
         self.image_black = Image.new('1', (self.wt, self.ht), 255) #255: clear the frame
         self.draw_black = ImageDraw.Draw(self.image_black)
-        self.mode = mode
+        self.bwMode = bwMode
+        self.scaleMode = scaleMode
         self.updateWidget(Image.open(img))
 
     def resizeImg(self, img):
@@ -104,7 +105,7 @@ class ImageWidget():
         print(" ratios are equal, not limited")
         return fixedImg
 
-    def zoomImg(self, img):
+    def fillImg(self, img):
     	#enlarge the image and crop to fill the widget canvas
     	iRatio = img.size[0]/img.size[1] #image ratio
         cRatio = self.wt/self.ht #canvas ratio
@@ -112,30 +113,40 @@ class ImageWidget():
         	print("new sizes as calcd in resize: "+str(self.wt)+" "+str(self.wt/iRatio))
         	fixedImg = img.resize((self.wt, int(self.wt/iRatio))) #width = wt, calc new height w/ ratio
       		offset = 0.5*(fixedImg.size[1] - self.ht) #centre by height
-      		cropped = fixedImg.crop((0, offset, self.wt, offset+self.ht))
+      		cropped = fixedImg.crop((0, offset, self.wt, offset+self.ht-1))
-      		cropped.load()
+      		#cropped.load()
       		print("zoomed to fill height")
       		return cropped
         if cRatio < iRatio:
         	fixedImg = img.resize((int(self.ht*iRatio), self.ht)) #height = ht, calc new width w/ ratio
     		offset = 0.5*(fixedImg.size[0] - self.wt) #centre by width
-      		cropped = fixedImg.crop((offset, 0, offset+self.wt, self.ht))
+      		cropped = fixedImg.crop((offset, 0, offset+self.wt, self.ht-1))
-      		cropped.load()
+      		#cropped.load()
       		print("zoomed to fill width")
       		return cropped
       	print("not zoomed")
       	return img.resize((self.wt, self.ht))
 
+    def autoThresholdLimit(self, img):
+    	gscale = img.convert(mode="L")
+    	gscale.save("greyscale.bmp")
+    	extrema = gscale.getextrema()
+    	print("EXTREMA: "+str(extrema))
+    	limit = extrema[0] + 0.4*(extrema[1]-extrema[0])
+    	print(limit)
+    	self.thresLim = limit
+
     def threshold(self, val):
-        if(val>100):
+        if(val>self.thresLim):
             return 1
         else:
             return 0
 
     def bwImg(self, img):
-        if self.mode is "mono":
+    	self.autoThresholdLimit(img)
+        if self.bwMode is "mono":
             return img.convert('L').point(self.threshold, '1')
-        if self.mode is "dither":
+        if self.bwMode is "dither":
             return img.convert(mode='1')
 
     def pasteImg(self, img):
@@ -154,7 +165,12 @@ class ImageWidget():
         self.image_yellow.save("imgYellowWidget.bmp")
 
     def updateWidget(self, img):
-        rsImg = self.resizeImg(img)
+        if self.scaleMode is "fill":
+        	rsImg = self.fillImg(img)
+        if self.scaleMode is "resize":
+        	rsImg = self.resizeImg(img)
+        if self.scaleMode is "none":
+        	rsImg = img
         rsImg.save("rsImg.bmp")
         newImg = self.bwImg(rsImg)
         newImg.save("bwImg.bmp")