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• How can I resize an image then centralize it with a white background ? Can it be done using php-Imagine library ?

  6 février 2017, par BOBO

  The effect I would like to generate is exactly like the example in
  this StackOverflow thread : (Related Question)

  1.Resize image
  2.Keep proportion
  3.Add or Fill none-image areas with white background

  Here are three examples of this process below :
  1. If original is square no matter 640*640 or 1024*1024, just resize it to target dimension e.g. 480*480 will work.
  

  2. If the original input is vertical rectangular,the output should not be cropped
     and still be centerlized as below (the red dash edge marker is just make it easier to see the background is white and the proportion is kept after image resized to 480*480 px)
     

  3. if the original input is horizontal rectangular, output like below, white background, keeps proportion and image uncroped , thus without losing anything after the image processing.
     

  So after I’ve clarified such a question,
  I would like to know :

  1. Is there a general name of such Custom Image Resize mentioned above ?
  2. would like to know how to achieve it using php image library Imagine ?
     is it doable using php-imagine, or have to switch to another library, e.g imagemagick ?

  P.S. If you would like to achieve the effect either in image-resizing or video resizing, you can use below FFMPEG single-line command.
  (thanks to @Mulvya, yes below code applies both to videos and image formats)

  [run below built-in code in ffmpeg console to achieve the mentioned resize effect]

  [video resize]

  ffmpeg -i "[raw video url or videofile location.mp4]"  -vf "scale=iw*min(480/iw\,480/ih):ih*min(480/iw\,480/ih),pad=480:480:(480-iw)/2:(480-ih)/2:color=white" [save_path_and_filename].mp4  

  [image resize]

  ffmpeg -i "[raw image url or imagefile location.jpg]"  -vf "scale=iw*min(480/iw\,480/ih):ih*min(480/iw\,480/ih),pad=480:480:(480-iw)/2:(480-ih)/2:color=white" [save_path_and_filename].jpg

• ffmpeg : pad filter with transparent background for GIF input/output ?

  23 janvier 2023, par Yami Odymel

  I'm trying to pad the GIF source to a square thumbnail and the extended area should be transparent.

  


  (image source : https://store.steampowered.com/app/2113680/The_Dot/)

  


  

  


  To achieve the goal, I used the following command :

  


  ffmpeg -i ./test/source.gif -filter_complex "[0]scale=255:144[s1];[s1]pad=256:256:0:-56:blue[s2];[s2]split[s3][s4];[s3]palettegen=reserve_transparent=on:transparency_color=blue[p];[s4][p]paletteuse[s5]" -map [s5] -loop 0  ./test/output.gif -y


  


  


  1. [0]scale=255:144[s1]
     First I scale down the image.

     


  


  2. [s1]pad=256:256:0:-56:blue[s2]
     Then pad the image with an uncommon background color : blue

     


  


  3. [s2]split[s3][s4]
     And I split to two streams. One for palettegen and another for paletteuse.

     


  


  4. [s3]palettegen=reserve_transparent=on:transparency_color=blue[p]
     Generate the color palette that indicates blue as the transparency_color

     


  


  5. [s4][p]paletteuse[s5]
     Use the new color palette for output. The padded image with blue background color should be treated as a transparent background.

     


  


  


  But the output animated GIF still has a visible blue background color no matter if I put the paletteuse at first or in the end.

  


  

  


  Related posts :

  


  

  • Making GIFs with ffmpeg : what does "transparency_color" do ?

  


  • How do I resize an animated GIF and keep transparency ?

  


  • Transparency is gone while resizing (scaling) gif using ffmpeg

  


  


• Create a video with 5 images with fade in/out, zoom pan, and slide left/right

  16 mars 2016, par Sushovan Mukherjee

  I have to create a video with 5 different images 3 sec for each with the following sequence

  1. Fade Out
  2. Fade In
  3. Zoom
  4. Slide Left
  5. Slide Right

  I do not know about sliding filter command and also zooming is not working correctly.

  I am using the following command :

  ffmpeg \
  
  -loop 1 -t 3 -i img001.png \
  
  -loop 1 -t 1 -i img002.png \
  
  -loop 1 -t 3 -i img003.png \
  
  -loop 1 -t 3 -i img004.png \
  
  -loop 1 -t 3 -i img005.png \
  
  -c:v libx264 \
  
  -filter_complex \
  
  "[0:v]fade=t=out:st=2.5:d=0.5[v0]; \
  
   [1:v]fade=t=in:st=0:d=0.5,fade=t=out:st=2.5:d=0.5[v1]; \
  
   [2:v]zoompan=z='zoom+0.001':d=10:s=1200x478[v2]; \
  
   [3:v]fade=t=in:st=0:d=0.5,fade=t=out:st=2.5:d=0.5[v3]; \
  
   [4:v]fade=t=in:st=0:d=0.5,fade=t=out:st=2.5:d=0.5[v4]; \
  
   [v0][v1][v2][v3][v4]concat=n=5:v=1:a=0,format=yuv420p[v]" -map "[v]" out.mp4