Is there a way in Gambas to reduce the file size of an image/picture without shelling?

Save as jpeg not png

Or use picture.save compression/quality settings.
Read wiki on how the quality option works as it different for different file types.

I found a long time ago that saving a screenshot for the mailing list as png will not send as there's a file size limit. Save as jpeg though and all is okay <EMOJI seq="1f60a" tseq="1f60a">😊</EMOJI>

 Like this perhaps…
Picture.Load(sPath).Save(sPath, 0)

Re quality settings: for jpeg it affects quality for png it affects compression.

Wow , thanks cogier for the question and thanks @Bruce for your knowledge

I didn't know about this, and happy to learn something "new"  

/comp/gb.qt4/image/save - Gambas Documentation

Thanks Bruce. I have discovered that saving 101 images as .png is SLOW!!. I got much better results with .jpg files. This is the code I used for testing: -


Interestingly, just saving a 6.2MB .png as a .jpg reduced the file size to 1.5MB.

The Quality part of Sub Save ( Path As String [ , Quality As Integer ] ) seems to be logarithmic. The image below shows the value (Quality) used, the new file size in kb and the percentage of the original picture.

<IMG src="https://www.cogier.com/gambas/PictCompression.png"> </IMG>

It makes no sense. I tried the above code with a 2.4MB .jpg file and this time I finished with a file size of 5.7MB, which is over twice as large as the original!

<IMG src="https://www.cogier.com/gambas/PictCompression2.png"> </IMG>

 i looked up jpeg quality and from what i can tell "medium" quality is considered between 80%-90%
so higher must be adding data.

I remember having this issue once when i was loading and saving an image.

png may be slower but png is "lossless" so possibly the best way to get the smallest file with no loss of quality.