Video editors and visual effects (VFX) artists frequently encounter footage that requires localized modifications: removing an unwanted branded logo, swapping out a handheld prop, altering an actor's wardrobe, or cleaning up background distractions. Traditionally, this process demands meticulous frame-by-frame rotoscoping, planar tracking, and complex 3D compositing. Haiper provides an AI-native alternative through its Repaint your Video (Video-to-Video) engine and Vary Region inpainting tool, allowing creators to isolate specific elements on video clips and regenerate them using natural language prompts.
This guide outlines how video professionals can execute localized object replacement and element modification in Haiper, from mask creation and prompt engineering to practical production integration and post-pipeline finishing.
What Haiper Video Repainting Does
Haiper's video generation platform includes four primary creation modes: Create Video With Text, Animate Your Image, Repaint Your Video, and Extend Your Video.
The Repaint your Video mode operates as a video-to-video diffusion workflow. Instead of generating novel footage from scratch, the model takes an existing video clip as a structural and temporal baseline. Within this mode, the Vary Region tool introduces selective inpainting:
- Isolated Inpainting: You paint a mask directly over an element on the video's opening frame.
- Selective Regeneration: The AI recalculates and regenerates only the pixels bounded by the masked area across the duration of the clip, preserving unchanged surrounding video, backgrounds, and camera movements.
- Natural Language Control: The contents of the masked region are steered by a descriptive text prompt, enabling object replacement, element alteration, or total removal.
Step-by-Step Workflow: Replacing and Modifying Elements
Step 1: Access the Repaint Workspace
You can launch the repainting interface through two main entry points:
- Direct Mode Selection: On the Haiper Web App (
app.haiper.ai/creations) or iOS App, open the Creation Mode selector (via the + icon) and choose Repaint your Video. Upload your source video file (MP4 or MOV). - From Creation History: If you are working on a clip previously generated on Haiper, hover over the video in the results display or history panel and select the Edit / Repaint icon to send the clip directly into the repainting workflow.
Step 2: Define the Mask with "Vary Region"
Once your clip is uploaded, Haiper presents the Vary Region canvas displaying the first frame of your video:
- Adding Mask Areas (
+Brush): Select the+tool to paint over the object or region you wish to replace or modify. - Subtractive Trimming (
-Brush): Use the-tool to erase accidental mask spillover, keeping the mask clean around edge boundaries. - Mask Refinement Controls: Use the Undo, Redo, or Reset buttons if your brush stroke requires adjustment.
Production Tip: Expand Mask Padding Slightly
Never paint a tight, skin-tight mask directly against the subject's contours. Always paint roughly 5% to 15% beyond the object's silhouette. This extra margin provides the diffusion model with critical spatial context—such as neighboring surface textures, ambient lighting, and contact shadow gradients—enabling smooth edge blending between the regenerated area and original footage.
Step 3: Engineer the Text Prompt
The prompt determines how the masked area transforms. How you construct the prompt depends on whether you are replacing, modifying, or removing an element:
1. Object Replacement
Specify the new item, its materials, and how lighting interacts with it:
- Example: Instead of typing
"a cup", write"an antique brass goblet resting on the rustic wooden table, soft warm ambient lighting, highly detailed surface texture". - Contextual Anchor: Referencing nearby background elements (e.g., table material, lighting angle) guides the model to match ambient lighting and perspective.
2. Element and Attribute Modification
Keep the base subject identity but modify specific textures, colors, or visual styles:
- Example: Highlighting an actor's coat:
"a weathered dark-brown leather motorcycle jacket with metallic zipper accents, natural daylight shadows".
3. Object Removal (Clean Plate Inpainting)
To eliminate an object or distraction, avoid negative phrasing like "remove the trash can". The diffusion model responds best to positive descriptions of what should exist in that empty space:
- Example: Painting over a modern sign in historical footage:
"weathered red brick wall, matching mortar lines, natural outdoor daylight, seamless texture".
Step 4: Configure Settings and Generate
Before initiating generation, verify your generation parameters in the settings panel:
- Duration: Haiper natively handles 2-second and 4-second clip generations. For commercial workflows, 2- to 4-second iterations are optimal for maintaining spatial integrity.
- Seed Locking: If a particular generation yields favorable motion and lighting but the object details need refinement, lock the Seed value and tweak your prompt phrasing incrementally.
- Aspect Ratio: Repainting inherits the aspect ratio of the imported source video (standard ratios include 16:9, 9:16, 1:1, 4:3, and 21:9).
- Execution: Click Generate. The job is submitted to the processing queue.
Technical Constraints and VFX Production Realities
While Haiper's Vary Region tool accelerates rotoscoping and replacement tasks, VFX artists and editors should design their pipelines around the current technological characteristics:
1. First-Frame Masking vs. Temporal Tracking
Haiper's Vary Region mask is drawn on the video's first frame. The model then propagates the inferred regional modification forward through subsequent frames using internal temporal attention weights.
- Best Use Case: Locked-off tripod shots, slow dolly movements, or subjects with moderate motion.
- Challenging Conditions: Fast, erratic pans, rapid zooms, or objects that pass behind foreground occluders. In these scenarios, the model may experience temporal drift or edge boiling.
2. Resolution and Quality Management
Haiper Video 2.x supports 540p and 720p native generation, with 1080p enhancement passes available. For high-resolution delivery (4K film or broadcast master outputs), VFX artists should treat Haiper clips as generative asset plates, upscaling or blending them back into high-bitrate master sequences in post.
3. Credit Consumption and Licensing
- Under the Haiper Video 2.x model, Video-to-Video processing is priced at 8 credits per second at 720p. Haiper Video 1.5 standard generations cost 5 credits per second.
- Free tier accounts offer limited daily generation credits with watermarked exports.
- Professional workflows require a paid Haiper Membership to unlock watermark-free exports, commercial utilization rights, and higher concurrent generation slots.
Professional Post-Production Integration
To incorporate Haiper repainting into a standard NLE or compositing pipeline (such as Adobe Premiere Pro, DaVinci Resolve, or After Effects):
- Isolate Short Sub-Clips: In your NLE, trim the exact scene segment requiring modification into a 2- to 4-second sub-clip before uploading to Haiper. Shorter durations significantly reduce temporal jitter.
- Layer Compositing: Import the repainted clip back onto a video track above your original footage.
- Edge Masking and Feathering: Apply a soft garbage matte in your NLE around the modified area. Because you expanded the mask during generation, a feathered matte in post-production cleanly hides any slight background color shift between the AI plate and original raw footage.
- Grain and Noise Matching: AI video generation inherently denoises the regenerated area. Apply a matching film grain or sensor noise plugin (such as DaVinci Resolve Film Grain) to match the repainted patch with the native camera sensor noise.
- Color Grading: Perform a unified color grade across the composite to harmonize contrast and black levels.