OPF Image Treatment
Caption Overlay
A compact caption bar attaches attribution, source, or interpretation directly to an image.
Best Fit
Research images, press photos, product screenshots, and data-story evidence slides.
Photography Guidance
Keep the caption outside the subject's focal area. Use captions to clarify provenance or meaning, not to repeat the slide title.
Avoid
Avoid captions that cover faces, product UI, or the main evidence in the image.
Treatment Practices
Treat captions as metadata, not primary copy.
Use a solid or translucent caption surface with adequate contrast.
Keep captions short enough to read in one glance.
OPF Config
image-treatments:caption-overlay{
"$schema": "https://openpresentation.org/schema/opf/v1",
"name": "PPTX.gallery — image-treatments/caption-overlay",
"description": "A compact caption bar attaches attribution, source, or interpretation directly to an image.",
"tags": [
"gallery:image-treatments/caption-overlay"
],
"design": {
"slideImage": {
"src": "asset:hero",
"position": "background"
},
"imageFill": "crop"
},
"slides": [
{
"id": "gallery-preview-1",
"layout": "title-slide",
"title": "Caption Overlay",
"subtitle": "Research images, press photos, product screenshots, and data-story evidence slides.",
"image": {
"src": "asset:hero",
"alt": "Caption Overlay image treatment example"
},
"design": {
"contentBox": false,
"contentAlignment": "center",
"titleAlignment": "center"
}
}
],
"catalogs": {
"layouts": {
"records": [
{
"$schema": "https://openpresentation.org/schema/opf-layout/v1",
"id": "title-slide",
"name": "Title_Slide",
"label": "Title Slide",
"summary": "Bold, centered typography with minimal elements. Perfect for opening your presentation with impact.",
"description": "Bold, centered typography with minimal elements. Perfect for opening your presentation with impact.",
"tags": [
"Opening",
"Impact",
"Minimal"
],
"master": "Gallery",
"masterSlideIndex": 0,
"groupHash": "ddf3a920a68b7a0316802c6a646bb4bb481c6f5a288d236ab3021b4b990d25c2",
"groupDefault": true,
"contentType": "Title",
"contentMultiple": "None",
"contentAlignment": "Center",
"contentBox": false,
"contentTypeChartPrimary": "None",
"contentTypeImageFill": "None",
"contentTypeListBullet": "None",
"contentTypeListHeading": false,
"slideTitle": true,
"slideTitleAlignment": "Center",
"slideImage": false,
"slideImageAlignment": "None",
"slideLayoutDirection": "None",
"zones": [
{
"role": "title",
"placeholder": "title"
},
{
"role": "subtitle",
"placeholder": "subtitle"
}
],
"preview": {},
"details": "Bold, centered typography with minimal elements. Perfect for opening your presentation with impact. OPF placeholders: title, subtitle.",
"category": "opening-closing",
"spatialCategory": "hero",
"contentTypeTags": [
"mixed",
"title"
],
"placeholders": [
{
"type": "title"
},
{
"type": "subtitle"
}
],
"slideSubtitle": true
}
]
}
}
}Preview this config live at pptx.dev/playground, or load it in the gallery visual editor.
Related How-To Articles
Playground deep linkHow to Add Images to PowerPoint Slides with pptx.dev
Learn how to embed images in PowerPoint presentations using the pptx.dev API — including cropped, fitted, and multi-image layouts.
How to Place, Size, and Overlay Images in PowerPoint
Master image placement, sizing, cropping, and overlay techniques to create polished, professional presentation slides.
How to Design Image-Focused Full-Bleed Slides in PowerPoint
Use full-bleed photography and imagery to create high-impact presentation slides that command attention.
General Image Rules
Crop with intent
Choose fit, position, and size based on the subject and message, not just available space.
Protect readability
Text over images needs enough contrast, an intentional overlay, or a separate text surface.
Respect image truth
Avoid filters or crops that distort evidence, screenshots, charts, or compliance imagery.
Keep a system
Use a small set of image treatments consistently so photo-heavy decks still feel coherent.