transparency

问题 I wanted to create a blank alpha image to parse some data from py-opencv and save it on an transparent background png file. I tried : blank_image = np.zeros((H,W,4), np.uint8) and blank_image = np.full((H, W, 4) , (0, 0, 0, 0), np.uint8) (H and W are Height and Width) Both still render a black background instead of a transparent one. how to get a blank alpha transparent image? Thanks in advance :) Edits: as mentioned by Mark Setchell: you need to specify the alpha channel on other colors

问题 I wanted to create a blank alpha image to parse some data from py-opencv and save it on an transparent background png file. I tried : blank_image = np.zeros((H,W,4), np.uint8) and blank_image = np.full((H, W, 4) , (0, 0, 0, 0), np.uint8) (H and W are Height and Width) Both still render a black background instead of a transparent one. how to get a blank alpha transparent image? Thanks in advance :) Edits: as mentioned by Mark Setchell: you need to specify the alpha channel on other colors

问题 I wanted to create a blank alpha image to parse some data from py-opencv and save it on an transparent background png file. I tried : blank_image = np.zeros((H,W,4), np.uint8) and blank_image = np.full((H, W, 4) , (0, 0, 0, 0), np.uint8) (H and W are Height and Width) Both still render a black background instead of a transparent one. how to get a blank alpha transparent image? Thanks in advance :) Edits: as mentioned by Mark Setchell: you need to specify the alpha channel on other colors

问题 I'm trying to make a window transparent so that only part of its contents are visible, I've tried using SetLayeredWindowAttributes to make this happen, this made the window transparent as I wanted, however it only works that way when part of the windows picture is outside of the visible area of my desktop. For some reason whenever the window is fully on screen it re-draws its black background (the color I use for transparency that's meant not to be seen.) Here is a video example of the

问题 I have already read many topics about opacity/transparency on Windows Forms in C#, but it's not the effect I would like to get. I would like Form to be 100% transparent, but transparency of the Panel was adjustable, and the transparency effect was transferred to the elements behind Form (Windows desktop, web browser e.t.c.). The attached photo shows the effect that I would like to get (I made them in a graphic program). I will be grateful for your help. 回答1: OP: If there is any other language

问题 JPG doesn't support transparency. Yet you can export an image with transparent areas from for example GIMP. In that case the transparent areas will show either black or white in your browser, Windows explorer or other software. I regularly receive such files that I need to process and provide in several smaller formats. I do that with some PHP script using the GD library. The problem is that it is unpredictable whether those areas will turn out black or white in the processed versions. Even

问题 First, I want to say that I am a newbie in direct2d usage. My final purpose is to have per pixel transparent window. I have found this nice article : https://docs.microsoft.com/en-us/archive/msdn-magazine/2014/june/windows-with-c-high-performance-window-layering-using-the-windows-composition-engine and it seems that it answers my question. Before writing my per-pixel transparent window, I just tried to test the code in that link. But when I run the program, the disk that should be displayed

问题 We are working on a Three.js based WebGL project, and have trouble understanding how transparency is handled in WebGL. The image shows a doublesided surface drawn with alpha = 0.7, which behaves correctly on its right side. However closer to the middle strange artifacts appear, and on the left side the transparency does not seem to work at all. http://emilaxelsson.se/sandbox/vis1/alpha.png The problem can also be seen here: http://emilaxelsson.se/sandbox/vis1/ Has anyone seen anything similar

问题 I have been experimenting with converting the custom attribute BufferGeometry example (https://threejs.org/examples/webgl_buffergeometry_custom_attributes_particles.html) into a fly through animation and I find that the sprites have dark backgrounds (and those that I create myself as well) if depthTest is set to true. See the image. The sprite in the custom attribute example has a transparent background but this appears to be ignored when it is rendered if depthTest is set to true. I have

问题 I have been experimenting with converting the custom attribute BufferGeometry example (https://threejs.org/examples/webgl_buffergeometry_custom_attributes_particles.html) into a fly through animation and I find that the sprites have dark backgrounds (and those that I create myself as well) if depthTest is set to true. See the image. The sprite in the custom attribute example has a transparent background but this appears to be ignored when it is rendered if depthTest is set to true. I have