Guidance and skills

Compression to the smallest strategy:

The JPG format has the smallest storage space and is also widely supported. You can convert PNG, TIFF format to JPG format picture first, and then compress it to achieve optimal storage.

Format space size comparison:

In PNG, JPG, TIFF, HEIC four formats. You must understand the following basic concepts. The following table is the same original image data:

Format	Support Transparent (Alpha)	Same original image size	After compression	Applicable
PNG	Yes	1.3 MB	332 KB	Design
JPG	No	143 KB	109 KB	Website
TIFF	Yes	1.2 MB	340 KB	Design
HEIC	No	74 KB	Lowest	Apple

The same picture space size, you should pay attention to the format conversion:

PNG ≈ TIFF> JPG> HEIC

The image can be compressed to 60%-80% for the first time. The second and third compression changes are small, why?

The software compression strategy is: "Ensure that changes cannot be recognized by the naked eye, and compress as much as possible." If there is basically no change in compression again, it means that the picture has been compressed to the limit.

I need to compress the image to the smallest possible size, how do I do it? There are two cases

1. The original image is a JPG image, then drag it directly to ImageOptim to compress it.

2. The original image is in PNG, TIFF and other formats, then the image can be converted to JPG and then compressed.

What is the storage space for the same picture in different formats?

After comparing a lot of pictures, the author draws the following conclusion: the space occupied by the same picture: PNG ≈ TIFF> JPG> HEIC

Please select the appropriate format for conversion according to the extraction requirements.

Which picture format is best to choose?

This is analyzed according to specific needs. If you need a transparent channel (alph), then it is PNG. If there is no transparency, then the JPG space takes up less, of course the best.