alpha-transparency

问题 I need to split a webm encoded video into png frames, without losing transparency. I use the following ffmpeg command: ffmpeg -i dancer1.webm -pix_fmt rgba frames/%04d.png This produces a directory of pngs, but why is each output frame is missing transparency? I have used this example video, which contains an alpha channel. See it playing over a background here. Here's an example output frame from ffmpeg: ffmpeg produces the following output when it runs: ffmpeg version N-60294-g549f052

问题 I need to split a webm encoded video into png frames, without losing transparency. I use the following ffmpeg command: ffmpeg -i dancer1.webm -pix_fmt rgba frames/%04d.png This produces a directory of pngs, but why is each output frame is missing transparency? I have used this example video, which contains an alpha channel. See it playing over a background here. Here's an example output frame from ffmpeg: ffmpeg produces the following output when it runs: ffmpeg version N-60294-g549f052

问题 I'm trying to create a transparent gif through pillow in python through this code frames[0].save(path+'/final.gif', format='GIF', append_images=frames[1:], save_all=True, duration=33, loop=0,transparency=0) where frame is a list of PIL.Image files. The end result is that you can see the image in the previous frame This hasn't happened before and I was able to create this gif without any problems 回答1: I solved this problem by setting disposal = 2 , you can edit your code as: frames[0].save

来源： https://stackoverflow.com/questions/32161921/matplotlib-how-to-have-a-transparent-box-plot-face-while-a-non-transparent-line

问题 I am trying to make a glass plane by adjusting the translucency of the object with alpha values. Currently, it is a black plane as my alpha values have no effect on my objects. Please have a look at the image: glEnable(GL_BLEND); does nothing and glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO); makes all my objects disappear fragment shader: #version 330 core // interpolated values from the vertex shaders in vec3 vNormal; in vec3 vPosition; in vec2 vTexCoord; //

问题 I am trying to make a glass plane by adjusting the translucency of the object with alpha values. Currently, it is a black plane as my alpha values have no effect on my objects. Please have a look at the image: glEnable(GL_BLEND); does nothing and glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ZERO); makes all my objects disappear fragment shader: #version 330 core // interpolated values from the vertex shaders in vec3 vNormal; in vec3 vPosition; in vec2 vTexCoord; //

问题 This question already has answers here : Transparent images with C# WinForms (6 answers) Closed 6 years ago . Having two overlapping PictureBox controls, I'm trying to make the transparent areas of the picture box let the controls below (in the z-order) being visible. Even after trying what Microsoft suggests, I cannot get the desired result. This is what I currently have: And this is what I want: So my question is: Any way to achieve my desired result with two PictureBox controls (or with

问题 This question already has answers here : Transparent images with C# WinForms (6 answers) Closed 6 years ago . Having two overlapping PictureBox controls, I'm trying to make the transparent areas of the picture box let the controls below (in the z-order) being visible. Even after trying what Microsoft suggests, I cannot get the desired result. This is what I currently have: And this is what I want: So my question is: Any way to achieve my desired result with two PictureBox controls (or with

问题 Here's an interesting problem: I have a 2D "matrix" of double-precision, binary data I'd like to plot using Gnuplot. This is easily done as follows: plot "foo.dat" binary array=384x384 format='%double' with image The trick is that certain "regions" of the data have a special value, say 1234567890.0. I want those elements to be fully transparent, and all other matrix entires to be fully opaque. Is there a way to set the transparency channel based on the data itself? I have looked through the

问题 I'm new to Cairo, trying to create text with transparent color and stroke. stroke color's transparency works but text fill color transparency transparency_value doesn't work. If i reduce transparency_value , text color just gets darker(black) and increasing transparency_value makes text color brighter (green in my case) cairo_surface_t* surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 640, 480); cairo_t* cairo = cairo_create(surface); cairo_set_font_face(cairo, myfont_face); cairo