Python OpenCV 方法 | cv2.putText()

OpenCV Python 是一個 Python 鏈接庫，旨在解決計算機視覺問題。 cv2.putText () 方法用於在任意圖像上繪製文本字符串。

cv2 puttext

語法：cv2.putText(image, text, org, font, fontScale, color[, thickness[, lineType[, bottomLeftOrigin]]]) 參數：image ：要在其上繪製文本的圖像。

text：要繪製的文本字符串。

org：圖片中文本字符串左下角的坐標。坐標表示為兩個值的元組，即（X坐標值，Y坐標值）。

字體：表示字體類型。一些字體類型為 FONT_HERSHEY_SIMPLEX、FONT_HERSHEY_PLAIN 等。

fontScale：字體比例因子乘以特定字體的基本大小。

color：要繪製的文本字符串的顏色。對於 BGR，我們傳遞一個元組。 eg: (255, 0, 0) 表示藍色。

thickness：以px為單位的線條粗細。

lineType：這是一個可選參數。它給出了要使用的線的類型。

bottomLeftOrigin：這是一個可選參數。為真時，圖像數據原點位於左下角。否則，它在左上角。

返回值：它返回一個圖像。

如何使用 Python OpenCV2 在 windows 中的圖像上寫文字？

StackOverflow 問題

我想在上面放一些文字一個圖像。我將代碼編寫為：

cv2.putText(image,"Hello World!!!", (x,y), cv2.CV_FONT_HERSHEY_SIMPLEX, 2, 255) 

它給出錯誤，說`模塊`對像沒有屬性`CV_FONT_HERSHEY_SIMPLEX`

查詢可以` t 我使用上述字體類型？我在互聯網上搜索，但只找到與 Opencv C++ 相關的 initFont 語法。然後我想到了使用 putText 將字體類型作為參數傳遞。但它對我不起作用。

有什麼建議嗎？

答案：

此代碼使用 cv2.putText 在圖像上覆蓋文本。您需要安裝 NumPy 和 OpenCV。

import
 span> numpy as np import cv2 # 創建黑色圖像 img = np.zeros((512,512,3), np.uint8) # 寫一些文字 font = cv2.FONT_HERSHEY_SIMPLEX bottomLeftCornerOfText = ( 10,500) fontScale = 1 fontColor = (255,255,255) lineType = 2 cv2.putText(img,`Hello World!`, bottomLeftCornerOfText, font, fontScale, fontColor, lineType) #顯示圖片 cv2.imshow("img",img) #Save image cv2.imwrite ("out.jpg", img) cv2.waitKey(0) 

使用Python cv2.puttext在圖片中心寫文字

如果你知道你在圖片上寫的文字的形狀（寬，高），你可以把它放在中心在圖像上對齊。

上例中文本的大致形狀為 (268, 36)。您可能需要使用 Paint 或其他應用程序查找特定文本的形狀。

import numpy as np import cv2 image = cv2.imread(`sample.png`,cv2.IMREAD_UNCHANGED) position = ( (int) (image.shape[1]/2 - 268/2), (int) (image.shape[0]/2 - 36/2)) cv2.putText( image, #numpy array 寫入文本“Python 示例”，#text 位置，必須開始書寫的#position cv2.FONT_HERSHEY_SIMPLEX，#font family 1，#font size (209, 80, 0, 255)，#font color 3) #font stroke cv2.imwrite (`output.png`, image) 

輸出圖片：

Python OpenCV puttext

cv2 putte xt Example #

def detect(imgfile): origimg = cv2.imread(imgfile) img = preprocess(origimg) img = img.astype(np.float32) img = img.transpose((2, 0 , 1)) net.blobs[`data`].data[...] = img out = net.forward() box, conf, cls = postprocess(origimg, out) for i in range(len(box)) : p1 = (box[i][0], box[i][1]) p2 = (box[i][2], box[i][3]) cv2.rectangle(origimg, p1, p2, ( 0,255,0)) p3 = (max(p1[0], 15), max(p1[1], 15)) 標題 = "%s:%.2f" % (COCO_CLASSES[int(cls[i])] , conf[i]) cv2.putText(origimg, title, p3, cv2.FONT_ITALIC, 0.6, (0, 255, 0), 1) cv2.imshow("SSD", origimg) k = cv2.waitKey(0) & 0xff #Exit if ESC press if k == 27: return False return True 

cv2.puttext Example #

def drawBoundingBox(self,imgcv,result): for box in result : # print(box) x1,y1,x2,y2 = (box[`topleft`][`x`],box[`topleft`][`y`],box[`bottomright`][`x`] ,box[`bottomright`][`y`]) conf = box[`confidence`] # print(conf) label = box[`label`] if conf < self.predictThresh: continue # print(x1,y1,x2 ,y2,conf, label) cv2.rectangle(imgcv,(x1,y1),(x2,y2),(0,255,0),6) labelSize=cv2.getTextSize(label,cv2.FONT_HERSHEY_COMPLEX,0.5,2) # print(`labelSize> >`,labelSize) _x1 = x1 _y1 = y1#+int(labelSize[0][1]/2) _x2 = _x1+labelSize[0][0] _y2 = y1-int(labelSize[0][1]) cv2.rectangle(imgcv,(_x1,_y1),(_x2,_y2),(0,255,0),cv2.FILLED) cv2.putText(imgcv,label,(x1,y1),cv2.FONT_HERSHEY_COMPLEX,0.5,(0 ,0,0),1) return imgcv 

cv2 puttext Example #

def draw_labels(x, y, class_names=None): img = x.numpy() if img. ndim == 2 或 img.shape[2] == 1: img = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR) 盒子, classes = tf.split(y, (4, 1), axis=-1) classes = classes[..., 0] wh = np.flip(img.shape[0:2]) min_wh = np.amin(wh) if min_wh <= 100: font_size = 0.5 else: font_size = 1 for i in range( len(boxes)): x1y1 = tuple((np.array(boxes[i][0:2]) * wh).astype(np.int32)) x2y2 = tuple((np.array(boxes[i][ 2:4]) * wh).astype(np.int32)) img = cv2.rectangle(img, x1y1, x2y2, (255, 0, 0), 1) if class_names: img = cv2.putText(img, class_names[classes[i]], x1y1, cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, (0, 0, 255), 1) else: img = cv2.putText(img, str(classes[i]), x1y1, cv2.FONT_HERSHEY_COMPLEX_SMALL, 1, (0, 0, 255), 1) return img 

cv2.puttext Example #

def draw_outputs(img, outputs, class_names=None): box, objectness, classes = 輸出 #boxes, objectness, classes = boxes[0], objectness[0], classes[0] wh = np.flip(img.shape[0:2]) if img.ndim == 2 or img.shape[ 2] == 1: img = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR) min_wh = np.amin(wh) 如果 min_wh <= 100: font_size = 0.5 else: font_size = 1 for i in range(classes.shape[0 ]): x1y1 = 元組((np.array(boxes[i][0:2]) * wh).astype(np.int32)) x2y2 = 元組((np.array(boxes[i][2:4 ]) * wh).astype(np.int32)) img = cv2.rectangle(img, x1y1, x2y2, (255, 0, 0), 1) img = cv2.putText(img, `{}`.format( int(classes[i])), x1y1, cv2.FONT_HERSHEY_COMPLEX_SMALL, font_size, (0, 0, 255), 1) return img 

cv2 puttext Example #

def detect( imgfile): 原始文件= cv2.imread(imgfile) img = preprocess(origimg) img = img.astype(np.float32) img = img.transpose((2, 0, 1)) net.blobs[`data`].data[.. .] = img out = net.forward() box, conf, cls = postprocess(origimg, out) for i in range(len(box)): p1 = (box[i][0], box[i][ 1]) p2 = (box[i][2], box[i][3]) cv2.rectangle(origimg, p1, p2, (0,255,0)) p3 = (max(p1[0], 15) , max(p1[1], 15)) title = "%s:%.2f" % (CLASSES[int(cls[i])], conf[i]) cv2.putText(origimg, title, p3, cv2 .FONT_ITALIC, 0.6, (0, 255, 0), 1) cv2.imshow("SSD", origimg) k = cv2.waitKey(0) & 0xff #Exit if ESC press if k == 27: return False return True 

cv2.puttext Example #

def draw_boxes_frame(frame, frame_size, boxes_dicts, class_names, input_size): """在視頻幀中繪製檢測到的框""" boxes_dict = boxes_dicts[ 0] resize_factor = (frame_size[0] / input_size[1], frame_size[1] / input_size[0]) for cls in range(len(class_names)): boxes = boxes_dict[cls] color = (0, 0, 255 ) 如果 np.size(boxes) != 0：對於盒子中的盒子：xy = box[:4] xy = [int(xy[i] * resize_factor[i % 2]) for i in range(4)] cv2.rectangle(frame, (xy[0], xy[1]), (xy [2], xy[3]), 顏色[::-1], 2) (test_width, text_height), 基線 = cv2.getTextSize(class_names[cls], cv2.FONT_HERSHEY_SIMPLEX, 0.75, 1) cv2.rectangle(frame , (xy[0], xy[1]), (xy[0] + test_width, xy[1] - text_height - 基線), color[::-1],粗細=cv2.FILLED) cv2.putText(frame , class_names[cls], (xy[0], xy[1] - baseline), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (0, 0, 0), 1) 

cv2 puttext Example #

def ProcessFrame(self, frame): # 分割手臂區域 segment = self.SegmentArm(frame) # 複製分割後的圖像在 draw = cv2.cvtColor(segment, cv2.COLOR_GRAY2RGB) # 繪製一些幫助正確放置手 cv2.circle(draw,(self.imgWidth/2,self.imgHeight/2),3,[255,102,0],2) cv2.rectangle(draw, (self.imgWidth/3,self. imgHeight/3), (self.imgWidth*2/3, self.imgHeight*2/3), [255,102,0],2) # 找到分割區域的外殼，並在此基礎上找到 # c onvexity 缺陷 [contours,defects] = self.FindHullDefects(segment) # 根據輪廓和凸度缺陷檢測手指的數量 # 將屬於手指的缺陷繪製為綠色，其他為紅色 [nofingers,draw] = self.DetectNumberFingers(contours,缺陷, 繪製) # 在圖像上打印手指數 cv2.putText(draw, str(nofingers), (30,30), cv2.FONT_HERSHEY_SIMPLEX, 1, (255,255,255)) return draw 

cv2.puttext Example #

def vis_class(img, pos, class_str, bg_color): """可視化類。""" font_color = cfg.VIS.SHOW_CLASS.COLOR font_scale = cfg.VIS.SHOW_CLASS.FONT_SCALE x0 , y0 = int(pos[0]), int(pos[1]) # 計算文本大小。 txt = class_str font = cv2.FONT_HERSHEY_SIMPLEX ((txt_w, txt_h), _) = cv2.getTextSize(txt, font, font_scale, 1) # 放置文字背景。 back_tl = x0, y0 - int(1.3 * txt_h) back_br = x0 + txt_w, y0 cv2.rectangle(img, back_tl, back_br, bg_color, -1) # 顯示文本。txt_tl = x0, y0 - int(0.3 * txt_h) cv2.putText(img, txt, txt_tl, font, font_scale, font_color, lineType=cv2.LINE_AA) return img 

cv2 puttext Example #

def plot_one_box(x, img, color=None, label=None, line_thickness=None): # 在圖像上繪製一個邊界框 img tl = line_thickness or round(0.002 * (img.shape[0] + img. shape[1]) / 2) + 1 # 線條粗細 color = color or [random.randint(0, 255) for _ in range(3)] c1, c2 = (int(x[0]), int(x [1])), (int(x[2]), int(x[3])) cv2.rectangle(img, c1, c2, color, thickness=tl) if label: tf = max(tl - 1, 1) # 字體粗細 t_size = cv2.getTextSize(label, 0, fontScale=tl / 3,粗細=tf)[0] c2 = c1[0] + t_size[0], c1[1] - t_size[1] - 3 cv2.rectangle(img, c1, c2, color, -1) # 填充 cv2.putText(img, label, (c1[0], c1[1] - 2), 0, tl / 3, [225, 255 , 255], 厚度=tf, lineType=cv2.LINE_AA) 

cv2.puttext 示例#

def vis_det_and_mask(im, class_name, dets, mask, thresh=0.8): " ""檢測的可視化調試。""" n um_dets = np.minimum(10, dets.shape[0]) colors_mask = random_colors(num_dets) colors_bbox = np.round(np.random.rand(num_dets, 3) * 255) # 根據坐標排序rois，繪製上bbox first draw_mask = np.zeros(im.shape[:2], dtype=np.uint8) for i in range(1): bbox = tuple(int(np.round(x)) for x in dets[i, :4]) mask = mask[i,:,:] full_mask = unmold_mask(mask, bbox, im.shape) score = dets[i, -1] if score > thresh: word_width = len(class_name) cv2.rectangle( im, bbox[0:2], bbox[2:4], colors_bbox[i], 2) cv2.rectangle(im, bbox[0:2], (bbox[0] + 18 + word_width*8, bbox[ 1]+15),colors_bbox[i],粗細=cv2.FILLED) apply_mask(im, full_mask, draw_mask, colors_mask[i], 0.5) draw_mask += full_mask cv2.putText(im, `%s` % (class_name) , (bbox[0]+5, bbox[1] + 12), cv2.FONT_HERSHEY_PLAIN, 1.0, (255,255,255), 厚度=1) 返回 im