These ImageMagick commands process an input image, resizing, sharpening, and converting it to JPEG. They also apply effects to create a glow and potentially reduce noise by compositing modified copies of the image onto the original.

Run example

npm run import -- "reduce noise from images after resizing"

reduce noise from images after resizing

convert in.jpg -filter Box -resize 320x320+0+0 -unsharp 0x1+0.25+0 -quality 86% -sampling-factor 1x1 -write out.png out.jpg


convert input.jpg ( +clone -enhance -alpha on -channel alpha -evaluate multiply 0.25 ) -composite output.jpg

convert input.jpg ( +clone -despeckle -alpha on -channel alpha -evaluate multiply 0.25 ) -composite output.jpg

#!/bin/bash

enhance_and_composite() {
  local input_image=$1
  local output_image=$2
  local alpha_factor=0.25

  # Clone input image and enhance it
  local enhanced_image=$(convert "$input_image" +clone -enhance -alpha on -channel alpha -evaluate multiply "$alpha_factor")

  # Composite enhanced image with original image
  convert "$input_image" "$enhanced_image" -composite "$output_image"
}

# Example usage:
enhance_and_composite input.jpg output_enhanced.jpg

Let's break down these ImageMagick commands:

Command 1: Image Resizing, Sharpening, and Conversion

convert in.jpg -filter Box -resize 320x320+0+0 -unsharp 0x1+0.25+0 -quality 86% -sampling-factor 1x1 -write out.png out.jpg

• convert in.jpg: This starts the ImageMagick conversion process, taking "in.jpg" as the input image.
• -filter Box: Specifies the resampling filter to use during resizing. "Box" is a simple filter.
• -resize 320x320+0+0: Resizes the image to 320 pixels wide and 320 pixels high. The +0+0 part means no offset from the original image's top-left corner.
• -unsharp 0x1+0.25+0: Applies unsharp masking to sharpen the image. The parameters control the amount of sharpening.
• -quality 86%: Sets the JPEG compression quality to 86%.
• -sampling-factor 1x1: Specifies the downsampling factor for the image. 1x1 means no downsampling.
• -write out.png: Writes the intermediate result as a PNG file named "out.png".
• out.jpg: Writes the final output as a JPEG file named "out.jpg".

Command 2: Adding a Glow Effect

convert input.jpg ( +clone -enhance -alpha on -channel alpha -evaluate multiply 0.25 ) -composite output.jpg

• convert input.jpg: Starts the conversion process with "input.jpg".
• ( +clone -enhance -alpha on -channel alpha -evaluate multiply 0.25 ): This part creates a modified copy of the input image:
  • +clone: Creates a copy of the input image.
  • -enhance: Applies a general enhancement filter.
  • -alpha on: Makes sure the image has an alpha channel (transparency).
  • -channel alpha: Works only on the alpha channel.
  • -evaluate multiply 0.25: Multiplies the alpha channel values by 0.25, effectively making the image semi-transparent.
• -composite output.jpg: Composites (layers) the modified copy onto the original image, creating a glow effect.

Command 3: Removing Noise

convert input.jpg ( +clone -despeckle -alpha on -channel alpha -evaluate multiply 0.25 ) -composite output.jpg

• convert input.jpg: Starts the conversion process with "input.jpg".
• ( +clone -despeckle -alpha on -channel alpha -evaluate multiply 0.25 ): This part creates a modified copy of the input image:
  • +clone: Creates a copy of the input image.
  • -despeckle: Removes noise from the image.
  • -alpha on: Makes sure the image has an alpha channel (transparency).
  • -channel alpha: Works only on the alpha channel.
  • -evaluate multiply 0.25: Multiplies the alpha channel values by 0.25, effectively making the image semi-transparent.
• -composite output.jpg: Composites (layers) the modified copy onto the original image, potentially reducing noise while adding a subtle glow effect.

Let me know if you have any more questions!