1.9.8 - Incorrect "Automatic crop" Behavior on Transparent PNGs and Black Background Issue with SVG Files

[Thomas2718]

Hello,

I would like to report 2 issues.

Bug 1: “Automatic crop” Stops at Previously Deleted Areas in Transparent PNGs

Steps to reproduce:
1. Open the PNG image that contains transparency.
2. Delete part of the image so that the deleted area appears transparent.
3. Run the “Automatic crop” function.

Expected behavior:
The “Automatic crop” function should ignore fully transparent areas and crop the image tightly around the remaining visible content.

Actual behavior:
Although the deleted area still looks transparent, it seems to be treated as non-transparent internally. As a result, the auto-crop operation stops at the boundary of the deleted area, as if a new opaque edge were created there.


Bug 2: SVG Files Render with a Black Background

Steps to reproduce:
1. Open the SVG file.
2. View the image in the application.

Expected behavior:
The SVG should render with its intended background, and all shapes should display with correct colors.

Actual behavior:
The background becomes completely black, and only a small subset of shapes or elements display their correct colors. Most of the SVG content appears incorrect or invisible against the black background.


Thank you for looking into this.

[user0]

I cannot reproduce your bug1

but there is an issue with Zealous crop, it crops too much

zealous_crop_issue.png

[Thomas2718]

I cannot reproduce your bug1

but there is an issue with Zealous crop, it crops too much

zealous_crop_issue.png

Thank you for your reply.

I am using "Automatic Crop", not "Zealous Crop".
I also tested "Zealous Crop", and the result matches yours: "Zealous Crop" does not work correctly either.

To clarify the issue, I have updated the attachments and added more files.
Please refer to the original post.

[user0]

bug1
press Ctrl+H to see edited image w/o alpha channel - there will be white rectangle that you cut out
before cutting, change Background color from white to black in the Viewer Edit menu

[Thomas2718]

bug1
press Ctrl+H to see edited image w/o alpha channel - there will be white rectangle that you cut out
before cutting, change Background color from white to black in the Viewer Edit menu

Thanks for the reply. I have tested the workaround you provided and it works.
I’ve confirmed that a "Delete" operation results in (RGB=background color, Alpha=0). Since the Automatic Crop tool seeks an exact match with the reference pixel (at the corner, usually (0, 0, 0, 0) ), it causes a mismatch that stops the crop.


I understand this isn't strictly a bug now. However, I would like to offer some feedback on the underlying logic for future improvement:

In any image editing context, "Delete" implies that the area is no longer wanted. Logically, Alpha = 0 represents an unwanted area. In the context of an automatic crop, this intent should arguably have higher priority than an RGB mismatch.

Suggestion:

To improve the workflow, would it be possible to add a checkbox in the Automatic Crop settings to "Crop any pixel with Alpha = 0 regardless of its RGB value"?

This would ensure the tool remains reliable even when the user prefers a specific UI background color.

Thanks again for the support.