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AnorexicPig

macrumors 6502
Original poster
Dec 12, 2012
378
31
Winnipeg,Canada
Hi guys, I just bought Pixelmator, but if I apply any edit in it, the image file increases from around 8mb to 14 or in some cases to 22mb :eek:.

Is it normal ? I am using Aperture as a DAM.
 
Last edited:

zObsidian

macrumors member
Nov 25, 2010
53
0
What type of file are you editing and what are you saving it as? .pxm, .jpg, .png, .gif, .bmp?

Pixelmator's default file format is .pxm and it is typically larger than most other formats like .jpg because the .pxm file is considered your master file and contains a lot more information about the image, like alpha channels and layers, so it naturally has a large file size. Saving the same image as .jpg loses all this extra information.

If you are saving as a file format like .jpg, file size is affected by compression levels. Higher compression results in smaller file size and lower image quality. If you take an image with a high .jpg compression and save it with default settings (normal .jpg compression), you might end up with a larger file size. Editing and saving .jpgs is tricky business, since the .jpg format is a lossy format, meaning that it loses some picture quality each time you re-edit and re-save.

Otherwise, if you are saving between different file formats, the file size may also change. For example, converting a lossless compressed .png file as a .bmp which has no compression at all. Or saving a 24-bit .png file as a 32-bit .png file, the file size will also increase because you are including an additional alpha channel in addition to the standard RGB.

If you tell us the exact file formats you are using to open and save as, we can give you more details about why your file sizes are increasing.
 

AnorexicPig

macrumors 6502
Original poster
Dec 12, 2012
378
31
Winnipeg,Canada
What type of file are you editing and what are you saving it as? .pxm, .jpg, .png, .gif, .bmp?

Pixelmator's default file format is .pxm and it is typically larger than most other formats like .jpg because the .pxm file is considered your master file and contains a lot more information about the image, like alpha channels and layers, so it naturally has a large file size. Saving the same image as .jpg loses all this extra information.

If you are saving as a file format like .jpg, file size is affected by compression levels. Higher compression results in smaller file size and lower image quality. If you take an image with a high .jpg compression and save it with default settings (normal .jpg compression), you might end up with a larger file size. Editing and saving .jpgs is tricky business, since the .jpg format is a lossy format, meaning that it loses some picture quality each time you re-edit and re-save.

Otherwise, if you are saving between different file formats, the file size may also change. For example, converting a lossless compressed .png file as a .bmp which has no compression at all. Or saving a 24-bit .png file as a 32-bit .png file, the file size will also increase because you are including an additional alpha channel in addition to the standard RGB.

If you tell us the exact file formats you are using to open and save as, we can give you more details about why your file sizes are increasing.

Thanks for the detailed response. My photos in Aperture show as JPEG, but the ones which have been edited in Pixelmator show as TIFF,so any way of keeping the format of Pixelmator pics in JPEG ?

I basically use iPhone 5 as camera,save them to Aperture and then from today used Pixelmator.
 

sniffies

macrumors 603
Jul 31, 2005
5,644
14,608
somewhere warm, dark, and cozy
Old thread but still relevant:

Pixelmator has the worst Exporting algorithm.

I just opened a random JPEG in Pixelmator and applied ZERO edits, didn't touch a thing. Then I decided to export it as JPEG (100% quality obviously since imported at 100%) and guess what, it increased from the original 520 KB to a crazy 3.38 MB. What the actual F***??!!!

What the hell is goin' on with this app??
 
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