17-05-2021, 10:36 AM
JPEG file size is obviously a product of pixel count and compression ratio.
I can't see how to alter the compression ratio within MS Paint - from what I've read, I don't think you can.
With Paint Shop Pro, it's just a case of clicking the "Options" button within the File -> Save As dialogue.
Obviously, cascading JPEG coding should be avoided, just as you'd avoid cascading MPEG encoding in broadcasting. But if you have a camera that only produces JPEG files, then setting the camera to use the minimum JPEG compression is the best you can do, and the results are normally OK if you have to process the image and save it as a JPEG once or twice at a low compression ratio. Of course, if you're resizing for web use, then the resize operation will average out a lot of the JPEG artefacts from camera's encoding, so when you save as a JPEG you're almost starting afresh.
In terms of image quality, I can't see why it would matter whether you crop or resize first.
What hasn't been mentioned is sharpness. Image size reduction obviously involves low pass filtering, and in my experience all applications do it differently. The ability to alter the sharpness after resizing is something I value. Being honest, I tend to apply a tad too much sharpness - but never to the extent of causing ringing - I think it helps with technical images, but vary that approach for other things, like portraits, etc. I don't think you can change the sharpness settings in the PowerToy image resizer.
I can't see how to alter the compression ratio within MS Paint - from what I've read, I don't think you can.
With Paint Shop Pro, it's just a case of clicking the "Options" button within the File -> Save As dialogue.
Obviously, cascading JPEG coding should be avoided, just as you'd avoid cascading MPEG encoding in broadcasting. But if you have a camera that only produces JPEG files, then setting the camera to use the minimum JPEG compression is the best you can do, and the results are normally OK if you have to process the image and save it as a JPEG once or twice at a low compression ratio. Of course, if you're resizing for web use, then the resize operation will average out a lot of the JPEG artefacts from camera's encoding, so when you save as a JPEG you're almost starting afresh.
In terms of image quality, I can't see why it would matter whether you crop or resize first.
What hasn't been mentioned is sharpness. Image size reduction obviously involves low pass filtering, and in my experience all applications do it differently. The ability to alter the sharpness after resizing is something I value. Being honest, I tend to apply a tad too much sharpness - but never to the extent of causing ringing - I think it helps with technical images, but vary that approach for other things, like portraits, etc. I don't think you can change the sharpness settings in the PowerToy image resizer.
