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POST
/
v1
/
enhance-upscale
Enhance and Upscale Image
curl --request POST \
  --url https://api.legnext.ai/api/v1/enhance-upscale \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "image_url": "https://example.com/photo.jpg",
  "jobId": "1868588555208310784",
  "imageNo": 0,
  "target_resolution": "4K",
  "content_type": "photo",
  "aspect_ratio": "keep",
  "crop_mode": "letterbox",
  "output_format": "jpeg",
  "face_enhancement_level": "moderate",
  "callback": "https://your-domain.com/webhook"
}
'
{
  "code": 400,
  "message": "Invalid request, image_url must start with http:// or https://",
  "raw_message": "image_url must start with http:// or https://",
  "detail": null
}
Supports direct image URLs or images from previous Midjourney tasks.

​
Input Methods

Choose one of the following input methods:

​
Option 1: Direct Image URL

ParameterTypeRequiredDescription
image_urlstringYesPublicly accessible image URL (HTTP/HTTPS). Supports JPEG, PNG, TIFF. Max: 100MB

​
Option 2: Midjourney Task

ParameterTypeRequiredDescription
jobIdstringYesID from previous Midjourney task
imageNointegerYesImage index from grid (0-3)

​
Common Parameters

All enhancement requests support the following parameters:
ParameterTypeDefaultDescription
target_resolutionstring2KOutput resolution: HD, FHD, 2K, 4K, 6K, 8K, 12K
content_typestringstandardEnhancement model: standard, photo, illustration, text, low_res
aspect_ratiostringkeepAspect ratio: keep, 1:1, 16:9, 9:16, 4:5, 5:4, 3:2, 2:3, 4:3, 3:4
crop_modestringletterboxCrop handling: letterbox, crop, stretch
output_formatstringjpegOutput format: jpeg, jpg, png, tiff, tif
face_enhancement_levelstringmoderateFace enhancement: off, none, subtle, moderate, strong
callbackstring-Webhook URL for completion notifications

​
Resolution Options

ResolutionLong EdgeCreditsCostRecommended For
HD/FHD1920px120$0.12Web, social media
2K2560px120$0.12Web, social media (default)
4K3840px160$0.16Digital displays
6K6144px200$0.20Professional printing
8K7680px300$0.30Large format prints
12K12288px540$0.54Billboards, posters
Higher resolutions consume more credits and take longer to process. Choose the minimum resolution that meets your requirements.

​
Content Type Models

TypeBest For
standardGeneral purpose, mixed content (default)
photoPhotographs, realistic images
illustrationDigital art, CGI, drawings
textDocuments, screenshots with text
low_resVery low quality source images

​
Face Enhancement

LevelEffect
off / noneDisabled (no faces in image)
subtleGentle enhancement for natural portraits
moderateBalanced enhancement (default)
strongAggressive enhancement for low-quality faces

​
Examples

​
Using Image URL

curl -X POST "https://api.legnext.ai/api/v1/enhance-upscale" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "image_url": "https://example.com/photo.jpg",
    "target_resolution": "4K",
    "content_type": "photo"
  }'

​
Using Midjourney Task

curl -X POST "https://api.legnext.ai/api/v1/enhance-upscale" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "jobId": "1868588555208310784",
    "imageNo": 0,
    "target_resolution": "8K",
    "content_type": "illustration"
  }'

​
Response

​
Success Response

Returns a task object with the following structure: 
{
    "job_id": "f3efd852-18ad-483d-87f2-0685a60df014",
    "model": "midjourney",
    "task_type": "enhance_upscale",
    "status": "pending",
    "config": {
        "service_mode": "public",
        "webhook_config": {
            "endpoint": "",
            "secret": ""
        }
    },
    "input": null,
    "output": {
        "image_url": "",
        "image_urls": null,
        "seed": ""
    },
    "meta": {
        "created_at": "2025-12-17T03:22:29+08:00",
        "started_at": "0001-01-01T00:00:00Z",
        "ended_at": "0001-01-01T00:00:00Z",
        "usage": {
            "type": "point",
            "frozen": 300,
            "consume": 0
        }
    },
    "detail": null,
    "logs": [],
    "error": {
        "code": 0,
        "raw_message": "",
        "message": "",
        "detail": null
    }
}

​
Response Fields

FieldTypeDescription
job_idstringUnique task identifier (UUID)
modelstringModel used: midjourney
task_typestringTask type: enhance_upscale
statusstringCurrent status: pending, processing, completed, failed
configobjectService configuration
config.service_modestringService mode: public
config.webhook_configobjectWebhook configuration
config.webhook_config.endpointstringWebhook endpoint URL (empty if not set)
config.webhook_config.secretstringWebhook secret (empty if not set)
inputobject/nullInput parameters (null for this endpoint)
outputobjectTask output (empty until completed)
output.image_urlstringPrimary enhanced image URL (available when status is completed)
output.image_urlsarray/nullArray of enhanced image URLs (null until completed)
output.seedstringGeneration seed (empty for enhancement tasks)
metaobjectTask metadata
meta.created_atstringTask creation timestamp (ISO 8601)
meta.started_atstringTask start timestamp (ISO 8601, 0001-01-01T00:00:00Z if not started)
meta.ended_atstringTask completion timestamp (ISO 8601, 0001-01-01T00:00:00Z if not completed)
meta.usageobjectCredit usage information
meta.usage.typestringUsage type: point
meta.usage.frozenintegerCredits frozen/reserved for this task
meta.usage.consumeintegerCredits actually consumed (0 if task failed)
detailobject/nullAdditional task details (null if none)
logsarrayProcessing logs (empty array)
errorobjectError information
error.codeintegerError code (0 if successful)
error.raw_messagestringRaw error message from service (empty if successful)
error.messagestringHuman-readable error message (empty if successful)
error.detailobject/nullAdditional error details (null if none)
Use the job_id to check task status via the Get Task Status endpoint.

Authorizations

​
x-api-key
string
header
required

API key for authentication

Body

application/json
​
image_url
string<uri>
required

Direct image URL to enhance. Must be publicly accessible. Supports JPEG, PNG, TIFF formats. Maximum file size: 100MB.

Maximum string length: 2048
Example:

"https://example.com/photo.jpg"

​
jobId
string

Task ID from a previous Midjourney generation task. Use this to enhance images from prior generations.

Example:

"1868588555208310784"

​
imageNo
integer

Image index from the Midjourney grid (0-3). Required when using jobId.

Required range: 0 <= x <= 3
Example:

0

​
target_resolution
enum<string>
default:2K

Target output resolution. Higher resolutions cost more credits.

Available options:
HD,
FHD,
2K,
4K,
6K,
8K,
12K
Example:

"4K"

​
content_type
enum<string>
default:standard

Content-aware enhancement model selection.

Available options:
standard,
photo,
illustration,
text,
low_res
Example:

"photo"

​
aspect_ratio
enum<string>
default:keep

Output aspect ratio. Use 'keep' to maintain original proportions.

Available options:
keep,
1:1,
16:9,
9:16,
4:5,
5:4,
3:2,
2:3,
4:3,
3:4
Example:

"keep"

​
crop_mode
enum<string>
default:letterbox

How to handle aspect ratio changes when aspect_ratio is not 'keep'.

Available options:
letterbox,
crop,
stretch
Example:

"letterbox"

​
output_format
enum<string>
default:jpeg

Output image format.

Available options:
jpeg,
jpg,
png,
tiff,
tif
Example:

"jpeg"

​
face_enhancement_level
enum<string>
default:moderate

AI-powered face enhancement strength.

Available options:
off,
none,
subtle,
moderate,
strong
Example:

"moderate"

​
callback
string<uri>

Webhook URL for task completion notifications.

Example:

"https://your-domain.com/webhook"

Response

Enhancement task created successfully