Compress-Or-Die

PNG Compressor

4.49 kB

(-77.60%)
20.05 kB

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Learn more about PNG compression in my article Finally understanding PNG.

Preprocessing

100

Defines the dimensional size of the resulting image.


Removes any borders or edges of an image which did does not change in color or transparency.


0

The Selective Blur is used to blur a background so it can be better compressed.

Contrary to other blur algorithms, the Selective Blur doesn't act on all pixels: blur is applied only if the difference between its value and the value of the surrounding pixels is less than a defined threshold value. So, contrasts are preserved because difference is high on contrast limits.

0

The Selective Blur is used to blur a background so it can be better compressed.

Contrary to other blur algorithms, the Selective Blur doesn't act on all pixels: blur is applied only if the difference between its value and the value of the surrounding pixels is less than a defined threshold value. So, contrasts are preserved because difference is high on contrast limits.

Compression

8 bit
Creates a PNG with max. 256 colors and transparency.
24/32 bit
Creates a truecolor PNG with transparency if needed.
256

Specifies the amount of colors used to display the image.

Dithering is the process by which we create illusions of the color that are not present actually. It is done by the random arrangement of pixels.


Use more processor power to get a smaller image without affecting the image quality.
Be careful: This is time-intensive.

Compression view

Here you can see how efficient the compression of this PNG file is. Dark blue means this area could be well compressed and red means poorly compressed. You can use it for different things:

Dirty transparency detection
If you have fully transparent areas that are not shown in dark blue you know that there are visible pixels (perhaps with just 1% opacity) you should delete.
Broken repetition detection
If you have two objects in your PNG that should be absolutely equal but the second one is not shown in dark blue you know that they are not exatly the same. So you are losing much compression potential. Open the PNG in your graphics program to copy the object pixel-perfect. Remember the 32k sliding window imposed by the Deflate algorithm.

Result

Hover this area to show the original image

Original

Hover this area to show the original image

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