Batch Automation Batch Automation is increasing the size of my files

[danman03]

So, I had a client who wanted to add a watermark to their images. They had close to 700 images to watermark, so I decided to use the automated batch function to cut down on time. I made my own action and all that, but when I went back to look at the files, their size increased dramatically. The average size of the original png file I was watermarking was around 8mb. After I ran the automation of adding the watermark, the average size of the png went up to 42mb. As you can imagine, 700 images at 42mb is a HUGE folder size. When I go through and add a watermark individually and save it, the file stays the same size. So, something in the automation is making my files balloon in size. Does anyone have any idea what is causing the issue?

 

[thebestcpu]

Hi danman03

There could be a few different things going on and either could create such a large difference in file size.

1) The output pixel dimensions are larger than the original pixels dimentions. I bet you checked this already yet had to mention it.

2) The other that can commonly happen is the the PNG that your are opening is actually a PNG-8 file instead of PNG-24 file which is an indexed file. It has an embedded color table of the allowed colors in the image (aka indexed) and the the color table can be set to 256 or smaller. If it were a PNG-8 file with a color table of 64 colors, the file size would be about 1/5 of the PNG-24 file that you likely output from Photoshop. You can check if the opened file was indexed by looking at the Color Mode in the Image > Mode command. If it indicates "Indexed" then the read PNG was of the smaller type.

3) Another factor also could be that the image was in 8 bit color and you ouput in 16 bit color which is supported by PNG

So I bet it is one or more of the three items above yet thats just my best guess

Hope this helps

John Wheeler

BTW - If you want to output in PNG-8 you cna do that with the Save for Web approach and select PNG-8 and the color table size.

 

[danman03]

Hi danman03

There could be a few different things going on and either could create such a large difference in file size.

1) The output pixel dimensions are larger than the original pixels dimentions. I bet you checked this already yet had to mention it.

2) The other that can commonly happen is the the PNG that your are opening is actually a PNG-8 file instead of PNG-24 file which is an indexed file. It has an embedded color table of the allowed colors in the image (aka indexed) and the the color table can be set to 256 or smaller. If it were a PNG-8 file with a color table of 64 colors, the file size would be about 1/5 of the PNG-24 file that you likely output from Photoshop. You can check if the opened file was indexed by looking at the Color Mode in the Image > Mode command. If it indicates "Indexed" then the read PNG was of the smaller type.

3) Another factor also could be that the image was in 8 bit color and you ouput in 16 bit color which is supported by PNG

So I bet it is one or more of the three items above yet thats just my best guess

Hope this helps

John Wheeler

BTW - If you want to output in PNG-8 you cna do that with the Save for Web approach and select PNG-8 and the color table size.

Hey, thanks for the reply. I went back and looked at everything, but the originals weren't indexed, nor were they in PNG-8 or 8 bit color. The pixels were the same size as well. I ended up saving the new files as PNG-8 and it lowered the files considerably. So, that worked for me. I just wish I knew what was causing the issue.

 

[thebestcpu]

Hi danman03

Why don't you post the PNG file and if file size is too big to post on the Forum provide a link to the image(s) from file sharing site or dropbox etc. That way forum members could give it a look and probably give you a more definitive answer

Just a thought

John Wheeler