Questions tagged [alpha-channel]

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Convert this line to a VP8 line that allows me to render a PNG sequence

i want to convert this line ffmpeg -vcodec libvpx-vp9 -i original.webm -pix_fmt rgba frames/%04d.png that allows me to render a sequence png of a webm file that was originally in VP8
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Add Video With Alpha Channel On Top Of Another Video (FFMPEG) [duplicate]

I have two input files, one is a YUV h.264 mp4 file and the other is an 8-bit lossless unencoded RGBA .mov file output directly from After Effects. I would like to put the mov file with the alpha ...
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  • 958
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36 views

Working on a single in channel in GIMP

I'm using GIMP 2.10.22. I have an RGB color image, and I want to do work on one of the channels, without affecting the others. How can I copy the channel into a new image, work on it there, then copy ...
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  • 7,532
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1 answer
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ARGB in Adobe Illustrator

I need to create some icons and my client's requirements are (A: 0, R:255, G: 255, B: 255) for the background.  I'm working on Adobe Illustrator, how do I change the Alpha? When the background is ...
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1 answer
3k views

Transparent Video (RGB+Alpha) in PowerPoint

I am able to export a transparent-background video in After Effects - AVI with RGB+Alpha. It was of a man talking with a green screen background. However, once I import it to PowerPoint, a black ...
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1 vote
0 answers
310 views

ffmpeg stuck on last couple of frames during alphamerge

I'm trying to put alpha channel on an mp4 file, using an alpha file that I have previously extracted. The command that I'm using with some tuning flags is this: ffmpeg -hide_banner -i video.mp4 -i ...
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1 answer
2k views

ffmpeg merge videos including one with alpha transparency with mp3 audio

I have two video tracks (one with alpha transparency and both without audio) and an audio file, I need to put them all together with the same beginning. so: I only managed to mix the two videos ...
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2 votes
1 answer
429 views

Is it possible to compress alpha and RGB channels of PNG sequence separately with FFmpeg?

Suppose I have a sequence of 32-bit (RGBa) PNG files. Is it possible to compress the RGB channel with one codec and the alpha channel with another? For example, if I had the RGB and alpha as separate ...
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2 votes
1 answer
3k views

Lossless VP9 Webm Encoding of PNG Sequence with Alpha in FFmpeg

I'm trying to encode a sequence of 32-bit 8bpc PNG images (RGB with an alpha channel) using the lossless VP9 codec with ffmpeg; specifically: ffmpeg -framerate 60 -i out%04d.png -c:v libvpx-vp9 -...
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  • 958
3 votes
1 answer
3k views

Lossless Video Codec supporting Alpha Channels

Suppose I have a sequence of PNG image files which may or may not contain an alpha channel (assume those that do have an alpha channel actually utilize it). While PNG files themselves have their own ...
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  • 958
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1 answer
683 views

Alphamerge filter only works on first frame

I am trying to implement blur filter over specific non rectangle object, I have mask and sample video but the issue is that alphamerge result of first frame of video is applied to the whole video(Like ...
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1 answer
203 views

Convert bmp to png and black colors to alpha

I exported some sprites from the game Half-Life; however, they seem to have tones of black instead of the alpha channel. For example: How do I convert the black colors into alpha/transparency?
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2 votes
1 answer
151 views

Integrating ffmpeg4 with Pyglet. What is correct method to identify streams with alpha?

We're trying to interate ffmpeg4 with Pyglet. Its all going very well but we have one issue: If a VP9 (or VP8) file is created using ffmpeg4, from png files with alphas, we get a video file (webm) ...
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  • 121
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1 answer
322 views

How to get exact alpha value in Photoshop

I need to know the exact alpha value of a pixel in Photoshop. I tried using the answer in this question (Determine pixel alpha value in photoshop), but that gives me an opacity percentage such as 27%, ...
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0 answers
131 views

Apply depth of field blur effect from a grayscale video using ffmpeg [duplicate]

I have two videos. One is a normal video, the other is a grayscale video. Supposedly, merging the videos I can have a video with a depth of field blur effect. I wish to know how I could do it using ...
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121 views

How to concatenate different sized videos and then overlay with transparency on a background in ffmpeg?

I have multiple videos that are different sized, and I needed to concatenate them and then put the finished concatenated result on top of a 1080p background. However, the only way I can currently do ...
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9 votes
3 answers
13k views

Turn grayscale into alpha channel in Paint.net

I have a PNG image that has many shades of gray and no transparency: I would like to turn the grayscale into an alpha channel in Paint.net, so that the parts that are completely white would become ...
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1 vote
3 answers
10k views

ffmpeg -- How do I overlay a PNG over another PNG?

I have PNG A with alpha layer, which I want to overlay on top of another PNG B. How do I do that with ffmpeg? I tried ffmpeg -i A.png -i B -filter_complex "[0:v][1:v] overlay=0:0" out.png, but I ...
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2 votes
2 answers
2k views

How can you test a video with alpha channel before merging it with another video?

I am working on videos with alpha channel to be merged with a background video at a given position (for instance, [100,100]) . You can accomplish this by using: ffmpeg -i BACK -i OVER -...
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2 votes
1 answer
3k views

Using ffmpeg to create a video from a sequence of TGA images, with a depth of field blur effect sourced from the TGA's alpha channel

I'm working on turning a sequence of TGA images into a video using ffmpeg. I want the video to have a depth of field blur effect. The alpha channel of each TGA contains a depth-mask, where black=...
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1 vote
2 answers
3k views

Is it possible to overlay video with alpha channel over the desktop in real time (Windows)?

I'm going to run a pen & paper RPG game and one of my players will participate via Skype. To make his appearance more immersive, I would like to cast some sort of futuristic HUD over the video ...
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  • 13
0 votes
1 answer
88 views

How do I discard transparency channel when encoding files with bpgenc?

Sometimes png pictures contain redundant alpha channel. While this is usually not an issue, for libbpg it triggers more complicated mode which is not compatible with fast x265 encoding or with ...
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  • 16k
7 votes
1 answer
19k views

How do I add a background to a transparent png in gimp?

I have a png file with a transparent background. I would like to add a non-transparent background from a jpg. I have tried: Open the transparent png file. I see the picture with the checkerboard ...
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6 votes
1 answer
3k views

ffmpeg: change alpha channel of a showwaves filter

I've been trying to figure this issue out for a few hours and I can't seem to find any solution. I'm creating a video from an .mp3 and some images with the following command fmpeg.exe -y -i temp\...
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  • 136
3 votes
1 answer
2k views

overlay a sample video with alpha channel over another video in gstreamer

I want to play 2 video files using a GStreamer pipeline on my screen. The first video is without an embedded alpha channel and I want the second video with an embedded alpha channel to be overlaid ...
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  • 239
1 vote
0 answers
798 views

opensource vp6a encoding

I am looking for a way to encode a movie with vp6a. I was hoping I would be able to do this with ffmpeg using this command: ffmpeg -i test.flv -loop 1 -i bg.tga -vcodec vp6a -vframes 1037 -b:v 1024k -...
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  • 11
2 votes
1 answer
5k views

How do i convert a transparent .mov-file to an mp4 file overlayed on a background-image using FFMPEG

I'm trying to convert a mov file with the following specs: Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mov': Metadata: major_brand : qt minor_version : 537199360 ...
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  • 143
43 votes
1 answer
10k views

get pixel alpha value

Given a pixel in an image imported from a png file, how can I get the alpha value of the pixel with the GIMP? If this is not possible, what software can I use to achieve this (OS: Linux)?
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  • 1,175
1 vote
1 answer
419 views

How to combine multiple similar images with "holes" into one good one?

Suppose you have multiple photos of the same object (from slightly different angles), each have some obstacles in foreground. You added an alpha channel to each picture and "erased" the obstacle (...
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  • 16k
1 vote
0 answers
2k views

.MOV video compressed with PNG has no alpha channel

I have a QuickTime file .mov with alpha channel compressed with PNG codec. What I need is to create smaller version of this file using ffmpeg. Everything works except new mov has no alpha (Adobe After ...
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  • 21
1 vote
0 answers
279 views

Render Video as png with Alpha

I have pixel art that I want to put in an animated png. I animated it in the timeline, but when I rendered it into a series of pngs, It has no partial transparency. Anyone know how to solve this?
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  • 249
2 votes
1 answer
1k views

Keep alpha transparency in indexed PNG from Fireworks when batch resizing using convert (ImageMagick)

I have a special case where I'm using alpha transparency in indexed PNGs from Fireworks to keep the file size of PNG's in an iOS game down. (That is, indexed colors like an 8bit PNG but alpha ...
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0 votes
2 answers
84 views

How can I convert the color in this button into an alpha transparency so that any background will show through, changing the color of the button?

The button has a layer in it that has a bevel/emboss filter on it. I'm stumped. Here's the PSD that I'm trying to convert.
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5 votes
6 answers
9k views

Is there any way to save a PNG-8 file with Alpha Transparency in Photoshop?

I recently discovered something that I previous thought was impossible: PNG-8 files can store Alpha Transparency in the same way as PNG-32 files can. Not Indexed Transparency (like GIFs), but full on ...
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0 votes
1 answer
3k views

Convert TIFF with Alpha Channel to PNG?

I have a TIFF File that has a blue background and an Alpha Channel. I would like to save a PNG File which has the blue background transparent, using the Alpha Channel (because some pixels are not ...
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  • 3,081
13 votes
9 answers
29k views

Extracting the layer transparency into an editable layer mask in Photoshop

Is there any simple way to extract the "baked in" transparency in a layer and turn it into a layer mask in Photoshop? To take a simple example: Let's say that I paint a few strokes with a semi-...
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2 votes
1 answer
1k views

Alpha plugin in GStreamer not working

I'm trying to compose two videos, and I'm using the alpha plug-in to make the white color transparent. To test the alpha plug-in I'm creating the pipeline with gst-launch. The first test I done was: ...
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7 votes
3 answers
6k views

Point sample opacity/alpha in Adobe Photoshop?

I opened a PNG containing an alpha channel in Photoshop and wanted to get the opacity / alpha of a given point in the PNG file, so that I could match that opacity in a new photoshop layer. How can I ...
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