Saving Cropped JPEG Introduces Artifacts

[lzardy]

System information

• Windows OS version: 10
• ImageGlass version: 9.2.0.1208
• ImageGlass release: Classic

To Reproduce

Steps to reproduce the behavior:

1. Load an image
2. Enter crop mode and select an area to crop
3. Click save as... when finished
4. Save the cropped selection as a .jpg
5. Open the saved .jpg and zoom to see new jpeg artifacts

Actual behavior

• Saving cropped selections as JPG introduces new artifacts
• Parent image being a jpg does not affect the result
• New artifacts appear which are not present in the original image

Expected behavior

As a baseline, the behavior of the Save As... button should not apply any modifications if the resulting image type is the same as the currently loaded image. Alternatively (or as an additive) if ImageGlass is applying a jpeg compression algorithm, a menu should appear for options to modify the algorithm or disable it.

Screenshots / Video / Sample image file

Load the below images with "Scale to fit" to see the differences easier. The first image displays a normal cropped jpeg image (saved as png), with jpeg artifacts present around the edges of the black. The second image displays the "Save As..." cropped jpeg image, with new jpeg artifacts, and any previously existing artifacts are also modified.

Additional context

N/A

[d2phap]

Hi @lzardy,

ImageGlass does not focus on editing features (and I don't have much knowledge about it). You should use Copy file feature to make duplication. Saving image in ImageGlass does not guarantee the losslessness (a warning popup should have appeared when you save the image).

To adjust image quality, you can open Settings > Edit > Image quality.