Sage-Tips

How do I make an image transparent in OpenCV?

Transparent overlays with OpenCV

1. Use the cv2. rectangle function to draw a red bounding box surrounding myself in the bottom-right corner of the image.
2. Apply the cv2. putText method to draw the text PyImageSearch (along with the transparency factor) in the top-left corner of the image.

How do I extract an image from a video using OpenCV?

Steps:

1. Open the Video file or camera using cv2. VideoCapture()
2. Read frame by frame.
3. Save each frame using cv2. imwrite()
4. Release the VideoCapture and destroy all windows.

How do I add text to a video in OpenCV?

Python OpenCv: Write text on video

1. Parameters:
2. frame: current running frame of the video.
3. Text: The text string to be inserted.
4. org: bottom-left corner of the text string.
5. font: the type of font to be used.
6. color: the colour of the font.
7. thickness: the thickness of the font.

What does cv2 addWeighted do?

Alpha blending with OpenCV: cv2. Use cv2. addWeighted() to do alpha blending with OpenCV. It is calculated as follows according to parameters. The two images need to be the same size, so resize them.

Can OpenCV read PNG?

Read a Transparent PNG or TIFF in OpenCV A transparent image has four channels — 3 for color, and one for transparency. These images can be read in OpenCV using the IMREAD_UNCHANGED flag.

Can cv2 read PNG?

To read PNG images with transparency (alpha) channel, use cv2. IMREAD_UNCHANGED as second argument in cv2.

How do you make a video frame by frame in Python?

“python read a video frame by frame” Code Answer’s

1. import cv2.
2. vidcap = cv2. VideoCapture(‘big_buck_bunny_720p_5mb.mp4’)
3. success,image = vidcap. read()
4. count = 0.
5. while success:
6. cv2. imwrite(“frame\%d.jpg” \% count, image) # save frame as JPEG file.
7. success,image = vidcap. read()
8. print(‘Read a new frame: ‘, success)

What is cv2 waitKey?

cv2. waitKey(1) returns the character code of the currently pressed key and -1 if no key is pressed. the & 0xFF is a binary AND operation to ensure only the single byte (ASCII) representation of the key remains as for some operating systems cv2. waitKey(1) will return a code that is not a single byte.

What is cv2 Line_aa?

lineType : Type of line, whether 8-connected, anti-aliased line etc. By default, it is 8-connected. cv2. LINE_AA gives anti-aliased line which looks great for curves.

How do you make a video frame?

Turn an image sequence into a video

1. Fit the frame with borders or crop it.
2. Set the image duration.
3. Click the scissors icon to set the soundtrack duration manually or with the help of slidebars.
4. Choose an output format.
5. Click “Create” and get ready to check the result.

Should I use transparent or transparent overlays in OpenCV?

Great question. For starters, if your OpenCV app requires a Heads-up Display (HUD) of any kind, you should consider using transparent overlays. Instead of displaying runtime critical information in separate windowor in the terminal, you can directly overlaythe information on your output image.

How to blend the overlay image with the background image?

The following code will use the alpha channels of the overlay image to correctly blend it into the background image, use xand yto set the top-left corner of the overlay image.

How do you make a transparent overlay on an image?

In order to apply the transparent overlay, we need to make two copies of the input image: One for the final outputimage. And another for the overlaywe are about to construct. Using the cv2.rectanglefunction, we draw a rectangle surrounding myself in the bottom-right corner of the image.

How to draw text in pyimagesearch using CV2?

Using the cv2.rectanglefunction, we draw a rectangle surrounding myself in the bottom-right corner of the image. We then apply cv2.putTextto draw the text PyImageSearchin the top-left corner.