How to use the command optipng (with examples)

Optipng is a PNG file optimization utility that allows users to compress PNG files, reducing their file size without sacrificing image quality. It offers various compression options and can also manipulate metadata within the PNG file.

Use case 1: Compress a PNG with default settings

Code:

optipng path/to/file.png

Motivation: This use case is useful when you want to compress a PNG file without specifying any additional options. It will apply the default compression settings of optipng, optimizing the file size without compromising the image quality.

Explanation: This command runs optipng with the input file path/to/file.png. Without any additional options, it applies the default compression settings.

Example output:

**Processing:** path/to/file.png
   **New file size:** 542 bytes (2.1% improvement)

Use case 2: Compress a PNG with the best compression

Code:

optipng -o7 path/to/file.png

Motivation: This use case is useful when you want to achieve the highest level of compression for a PNG file. By specifying -o7, optipng applies the strongest compression algorithm, resulting in a smaller file size. However, this may increase the processing time.

Explanation: This command runs optipng with the input file path/to/file.png and sets the optimization level to 7 (-o7). The higher the optimization level, the stronger the compression applied.

Example output:

**Processing:** path/to/file.png
   **New file size:** 519 bytes (4.3% improvement)

Use case 3: Compress a PNG with the fastest compression

Code:

optipng -o0 path/to/file.png

Motivation: This use case is useful when you prioritize faster processing time over achieving the maximum compression. By specifying -o0, optipng applies the fastest compression algorithm, resulting in a quicker optimization process.

Explanation: This command runs optipng with the input file path/to/file.png and sets the optimization level to 0 (-o0). The lower the optimization level, the faster the compression process.

Example output:

**Processing:** path/to/file.png
   **New file size:** 572 bytes (bigger file size due to faster compression algorithm)

Use case 4: Compress a PNG and add interlacing

Code:

optipng -i 1 path/to/file.png

Motivation: This use case is useful when you want to optimize a PNG file for progressive loading, allowing the image to be displayed gradually. By adding interlacing, optipng organizes the image data in a way that enables quick rendering of a low-resolution preview.

Explanation: This command runs optipng with the input file path/to/file.png and specifies -i 1 to enable interlacing.

Example output:

**Processing:** path/to/file.png
   **New file size:** 546 bytes (1.3% improvement)

Use case 5: Compress a PNG and preserve all metadata

Code:

optipng -preserve path/to/file.png

Motivation: This use case is useful when you want to retain all metadata associated with a PNG file, including creation date, modification date, and other information. Preserving metadata can be important for archival, reference, or legal purposes.

Explanation: This command runs optipng with the input file path/to/file.png and uses -preserve to retain all metadata.

Example output:

**Processing:** path/to/file.png
   **New file size:** 539 bytes (1.7% improvement)

Use case 6: Compress a PNG and remove all metadata

Code:

optipng -strip all path/to/file.png

Motivation: This use case is useful when you want to remove all metadata from a PNG file, reducing its file size and potentially enhancing privacy by eliminating any embedded information.

Explanation: This command runs optipng with the input file path/to/file.png and uses -strip all to remove all metadata.

Example output:

**Processing:** path/to/file.png
   **New file size:** 531 bytes (2.9% improvement)

Conclusion:

Optipng is a powerful command-line tool for optimizing PNG files. By understanding the various use cases and options available, users can effectively compress PNG files to reduce file sizes, prioritize compression strength or processing speed, manipulate metadata, and improve the overall performance of web applications or storage systems that rely on PNG images.