Feature Request: Image highlighting

[bragiato]

Hi there,

First of all, I would like to thank you for this amazing tool. I have been using Sioyek for a long time, and it is by far my favorite PDF reader.

I would like to suggest some new functionalities regarding image handling. In the current version (Sep 11, 2024), it is not yet possible to highlight images or non-text areas. Here are a few ideas that could improve the workflow:

• Rectangular Image Highlights: It would be very useful if users could select a rectangular area on the screen and press a shortcut key (corresponding to a specific color) to create a highlight. Ideally, this would draw a semi-transparent colored rectangle over the selection.
• Integration with toggle_select_highlight: It would be excellent if the existing toggle_select_highlight command could be extended to work with these rectangular selections. If this mode is active, any rectangular area selected by the user would be automatically highlighted with the current highlight type, just as it currently works for text.
• Database Integration: To support this, perhaps a new table could be added to shared.db to store the coordinates, color codes, and image/page identifiers for these rectangular highlights.
• Modify Highlights: It would be great if users could click on these existing highlight rectangles to resize them or change the color, automatically updating the database.
• Copy Image from Highlight: Another helpful feature would be the ability to click a highlighted area and copy the underlying image/content directly to the clipboard.
• Image Highlight Panel (goto_image_highlights): Finally, a dedicated panel to visualize all image highlights in the document would be helpful. Similar to the current goto_highlight menu, this panel (perhaps called goto_image_highlights) would display all highlighted images stacked vertically for quick reference and navigation.

Thank you for your time and for developing such an indispensable tool.

Best regards.