Image Quality Degrades When Making Smaller

[lbohen]

I made an image smaller with Photo 2.5.4. The original image was very clear and 3102 x 1744 px at 144 DPI. When resizing to 200 x 112.4 px at 72 DPI the resulting image was blurry. See the attached smaller image.

Why would the image quality degrade?

How to prevent the image quality from degrading?

[Ldina]

Well, your original image has 5,409,888 pixels. Your downsized image has 22,480 pixels. So you are discarding 99.6% of all your pixels and the program is doing its best to preserve the quality with whatever resampling method you choose. Exporting has the same issues. That's a massive size change. 

If you start with a pixel based image, you can try downsampling in incremental steps and see if that helps, e.g., downsize by 50%, then again, etc, until you reach your desired size. Try different resampling algorithms....bilinear, bicubic, etc. If you notices a loss of quality in any of your steps along the way, you can try re sharpening before continuing to the next step. No guarantees.

Ideally, you'd want to create this job using vectors instead of pixels, especially since it is such a simple design. Then you can export to whatever size you want without any loss in quality. 

[Old Bruce]

51 minutes ago, lbohen said:

I made an image smaller with Photo 2.5.4. The original image was very clear and 3102 x 1744 px at 144 DPI. When resizing to 200 x 112.4 px at 72 DPI the resulting image was blurry. See the attached smaller image.

Why would the image quality degrade?

How to prevent the image quality from degrading?

I assume that the original is all vector work. Photo shows things as if they had been rendered down to Pixels. As @Ldina has pointed out the design is now only a tiny fraction of the original area. I would open the .afphoto in Designer, if you have it, and if the smaller image is still a vector only .afphoto document. Designer shows vectors as vectors, Photo shows vectors with a pixel view.

[Pšenda]

13 hours ago, lbohen said:

Why would the image quality degrade?

Why would the image quality degrade when the resolution is reduced? - try to answer yourself how quality and detailed a 1x1 pixel image will be.

 

13 hours ago, lbohen said:

When resizing to 200 x 112.4 px

Since pixels cannot be divided into smaller parts, the dimension you specify will always be rounded to whole pixels. However, this will change the aspect ratio of the new image, which must be recalculated, resulting in further degradation of image quality.