Std conversion of image file type creates files much much larger

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dec
Posts: 13
Joined: Sun Aug 07, 2022 4:18 am

Std conversion of image file type creates files much much larger

Post by dec »

converting JPG to PNG is creating files massively larger eg 1mb > 7mb
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xnview
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Re: Std conversion of image file type creates files much much larger

Post by xnview »

It's normal, JPEG is lossy format, and PNG is lossless format
Pierre.
dec
Posts: 13
Joined: Sun Aug 07, 2022 4:18 am

Re: Std conversion of image file type creates files much much larger

Post by dec »

this is not my experience with conversions with other graphics programs
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xnview
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Re: Std conversion of image file type creates files much much larger

Post by xnview »

could you post the ouput from XnView and from other app?
Pierre.
dec
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Joined: Sun Aug 07, 2022 4:18 am

Re: Std conversion of image file type creates files much much larger

Post by dec »

difficult because i do not want to upload 10mb files
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cday
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Re: Std conversion of image file type creates files much much larger

Post by cday »

You could possibly post screenshots of the viewer File > Properties... display for a JPEG, and for the same file converted to PNG by XnView MP, and if possible another software that you say produces smaller output sizes...

You might also look at the PNG save compression level set, the default values is 6 and I don't think increasing the value to the maximum of 9 reduces the filesize very much.

I believe without checking that the PNG format supports alternative compression methods, and that the content of the image being saved may also significantly affect the size of the output file, with areas of uniform colour possibly compressing very well.
dec
Posts: 13
Joined: Sun Aug 07, 2022 4:18 am

Re: Std conversion of image file type creates files much much larger

Post by dec »

thank you.
will check some things.