2007 m. birželis 25 d., pirmadienis 09:44, ying lcs raš?:

Hi,

How can I reduce the size of a png using gimp without losing much quality? Two ideas I have are:
1. reduce the color depth of the image 2. increase the compression level of in the png

Any more ideas? And can you please tell me how can I do #1, #2 in gimp?

Thank you.

And you can reduce size by
3. adjusting levels
and/or by
4. reduceing number of colours used.

By the way none of these ways is lossless. And you could use say jpg for smaller size. Or gif.

1. picture>mode>indexed 2. file>save as...>>Compresion level 1...9 9th level has best compression. You can choose some other options there too. 3.Layer>colors>levels
4. Layer>colors>color decrease (or something like that cause i use Gimp in my native language)

Hi!

On Monday 25 June 2007, ying lcs wrote:

Thanks. Can you please tell me how can I reduce the color depth of my png image?

It currently has 24 color depth. I would like to reduce it to 8. how can I do that in gimp?

Try:

Image -> Mode -> Indexed.

Regards,

Shlomi Fish

Thank you.

On 6/25/07, vt wrote:

2007 m. birželis 25 d., pirmadienis 09:44, ying lcs raš?:

Hi,

How can I reduce the size of a png using gimp without losing much quality? Two ideas I have are:
1. reduce the color depth of the image 2. increase the compression level of in the png

Any more ideas? And can you please tell me how can I do #1, #2 in gimp?

Thank you.

And you can reduce size by
3. adjusting levels
and/or by
4. reduceing number of colours used.

By the way none of these ways is lossless. And you could use say jpg for smaller size. Or gif.

1. picture>mode>indexed 2. file>save as...>>Compresion level 1...9 9th level has best compression. You can choose some other options there too. 3.Layer>colors>levels
4. Layer>colors>color decrease (or something like that cause i use Gimp in my native language)

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How can I reduce the size of a png using gimp without losing much quality? [...]

It's not gimp, but very nice for "crushing" PNG-files from the shell:

pngcrush

HTHT. Martin "vi"

2007 m. birželis 26 d., antradienis 06:24, ying lcs raš?:

Thanks. How about this idea? If my image has a white color as it background, will I save the image size if I convert my image to transparent?

Try and see:)

On 6/26/07, ying lcs wrote:

Thanks. I have tried it, but it does not help much. I wonder if I miss anything.

if you have any transparency in your image it will increase the size instead of shrinking it since it will add another channel to the image. To ensure you have no transparency in your image use image->flatten image

A good way to decrease the size of the image is to use either the indexed mode or just use colors->posterize to decrease the number of colors used. Be sure not to overwrite your original image since this is not a lossless operation