Notes

113 posts

Learning OpenCV 4: What Is an Image Histogram? How Do You Obtain One?

An image histogram is a statistical feature of image pixel values. It is inexpensive to compute and has many advantages, including invariance to image translation, rotation, and scaling. It is widely used across image processing, especially for grayscale image thresholding, color-based image retrieval, image classification, and backprojection tracking. Common types are grayscale histograms and color histograms.

【Learning OpenCV 4】Methods for Drawing Geometric Shapes

This article introduces methods for drawing rectangles, circles, lines, and ellipses with C++ and OpenCV 4. It focuses on the definitions of OpenCV built-in functions (such as rectangle(), circle(), line(), and ellipse()) and the role of each parameter, and provides example programs for reference. It also summarizes methods for drawing polygons, including the polygon-border drawing function polylines(), the polygon-filling function fillPoly(), the function for drawing multiple polygons drawContours(), and more.

[Learning OpenCV4] Image Channel Splitting, Merging, and Mixing Methods (C++)

After splitting image channels, the output multi-channel sequence is typically stored using std::vector mv;, where mv[0], mv[1], and mv[2] correspond to the three BGR channels respectively. However, what is displayed now is essentially three single-channel images—in other words, three grayscale images. To restore intuitive color to the three images, you need to use the channel merging method described below.

RobotStudio Study Notes, Part Five: Tool Data

Remove the gripper and measure the coordinates at the gripper tip. Click Modeling - Measure - Point to Point, select the gripper's base and end faces, and record the resulting z-coordinate value. Reinstall the gripper on the end of the robot. Open the Virtual FlexPendant, go to Manual Operation - Tool Coordinates - New, change the name, and click Initial Value in the lower-left corner. Set the first z (coordinate position) to the measured value, 215.30; set the mass parameter mass to 1; and enter an initial estimate for the second z (center-of-gravity position). Verify the coordinates, set Motion Mode to Reorient, and set Tool Coordinates to the coordinates created above. Moving the joystick shows the robot rotating about the center point between the two gripper tips.

LabVIEW Study Notes (VIII): Property Nodes

Property nodes provide access to object properties. In applications that may need to programmatically change the appearance of front panel objects in response to specific inputs, these changes can be configured by editing property nodes. Right-click a control on the block diagram to create a property node. To configure multiple properties, drag the top or bottom border to add properties. A property node executes its properties from top to bottom.