Computer Vision Helper The Computer Vision Helper skill guides you through implementing image analysis and visual AI tasks. From basic image classification to complex object detection and segmentation, this skill helps you leverage modern computer vision techniques effectively. Computer vision has been transformed by deep learning and now by vision-language models. This skill covers both traditional approaches (CNNs, pre-trained models) and cutting-edge techniques (CLIP, GPT-4V, Segment Anything). It helps you choose the right approach based on your accuracy requirements, available data, and deployment constraints. Whether you are building product recognition, document analysis, medical imaging, or any visual AI application, this skill ensures you understand the landscape and implement solutions that work. Core Workflows Workflow 1: Select Computer Vision Approach Define the task: Classification: What category is this image? Detection: Where are objects in this image? Segmentation: Pixel-level object boundaries OCR: Extract text from images Similarity: Find similar images Generation: Create or modify images Assess available resources: Training data quantity and quality Compute budget (training and inference) Latency requirements Accuracy needs Choose approach: Task No Training Data Small Dataset Large Dataset Classification CLIP, GPT-4V Transfer learning Fine-tune/train Detection GPT-4V, Grounding DINO Fine-tune YOLO Train custom Segmentation SAM Fine-tune SAM Train custom OCR Cloud APIs, Tesseract Fine-tune Train custom Plan implementation Document approach rationale Workflow 2: Implement Image Classification Prepare data:
Data loading with augmentation
transform
transforms . Compose ( [ transforms . Resize ( 256 ) , transforms . CenterCrop ( 224 ) , transforms . RandomHorizontalFlip ( ) , transforms . ColorJitter ( brightness = 0.2 , contrast = 0.2 ) , transforms . ToTensor ( ) , transforms . Normalize ( mean = [ 0.485 , 0.456 , 0.406 ] , std = [ 0.229 , 0.224 , 0.225 ] ) ] ) dataset = ImageFolder ( root = 'data/' , transform = transform ) dataloader = DataLoader ( dataset , batch_size = 32 , shuffle = True ) Set up model:
Transfer learning from pretrained model
model
models . resnet50 ( pretrained = True )
Freeze early layers
for param in model . parameters ( ) : param . requires_grad = False
Replace classifier head
model . fc = nn . Linear ( model . fc . in_features , num_classes ) Train with validation Evaluate on test set Optimize for deployment Workflow 3: Deploy Vision Model Optimize model: Quantization (INT8) Pruning ONNX export TensorRT optimization Set up inference pipeline: class VisionPipeline : def init ( self , model_path ) : self . model = load_optimized_model ( model_path ) self . preprocessor = ImagePreprocessor ( ) def predict ( self , image ) :
Preprocess
tensor
self . preprocessor . process ( image )
Inference
with torch . no_grad ( ) : output = self . model ( tensor )
Postprocess
- return
- self
- .
- postprocess
- (
- output
- )
- def
- predict_batch
- (
- self
- ,
- images
- )
- :
- tensors
- =
- [
- self
- .
- preprocessor
- .
- process
- (
- img
- )
- for
- img
- in
- images
- ]
- batch
- =
- torch
- .
- stack
- (
- tensors
- )
- with
- torch
- .
- no_grad
- (
- )
- :
- outputs
- =
- self
- .
- model
- (
- batch
- )
- return
- [
- self
- .
- postprocess
- (
- out
- )
- for
- out
- in
- outputs
- ]
- Deploy
- to target environment
- Monitor
- performance
- Quick Reference
- Action
- Command/Trigger
- Choose approach
- "What CV approach for [task]"
- Classify images
- "Build image classifier"
- Detect objects
- "Object detection for [use case]"
- Extract text
- "OCR from images"
- Zero-shot vision
- "Classify images without training data"
- Optimize model
- "Speed up vision model"
- Best Practices
- Start with Pre-trained
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- Don't train from scratch unless necessary
- ImageNet pre-trained models for general vision
- Domain-specific models when available
- CLIP/GPT-4V for zero-shot capabilities
- Data Quality Over Quantity
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- Clean, balanced data matters
- Remove mislabeled and duplicate images
- Balance classes or use weighted training
- Include edge cases in test set
- Augment Thoughtfully
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- Augmentation should reflect real variation
- Use augmentations that mirror production conditions
- Don't augment in ways that destroy task-relevant features
- Test that augmentation helps, don't assume
- Validate Correctly
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- Image data leaks easily
- Split by unique images, not by augmented versions
- Consider subject-level splits (same person in different photos)
- Test on truly held-out data
- Optimize for Target Hardware
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- Inference matters
- Know your deployment constraints (edge vs cloud)
- Profile and optimize bottlenecks
- Consider batch size for throughput
- Handle Edge Cases
- Real images are messy Different lighting conditions Rotation, blur, occlusion Unusual aspect ratios Out-of-distribution inputs Advanced Techniques Vision-Language Models for Zero-Shot Use CLIP for classification without training: import clip model , preprocess = clip . load ( "ViT-B/32" ) def zero_shot_classify ( image , labels ) :
Prepare image
image_tensor
preprocess ( image ) . unsqueeze ( 0 )
Prepare text prompts
text_prompts
[ f"a photo of a { label } " for label in labels ] text_tokens = clip . tokenize ( text_prompts )
Get embeddings
with torch . no_grad ( ) : image_features = model . encode_image ( image_tensor ) text_features = model . encode_text ( text_tokens )
Compute similarities
similarities
( image_features @ text_features . T ) . softmax ( dim = - 1 ) return { label : sim . item ( ) for label , sim in zip ( labels , similarities [ 0 ] ) } GPT-4V for Visual Analysis Use multimodal LLMs for complex vision tasks: def analyze_image ( image_path , question ) : import base64 from openai import OpenAI
Encode image
with open ( image_path , "rb" ) as f : image_data = base64 . b64encode ( f . read ( ) ) . decode ( ) client = OpenAI ( ) response = client . chat . completions . create ( model = "gpt-4-vision-preview" , messages = [ { "role" : "user" , "content" : [ { "type" : "text" , "text" : question } , { "type" : "image_url" , "image_url" : { "url" : f"data:image/jpeg;base64, { image_data } " } } ] } ] , max_tokens = 500 ) return response . choices [ 0 ] . message . content Object Detection with YOLO Fast, accurate object detection: from ultralytics import YOLO
Load pretrained model
model
YOLO ( "yolov8n.pt" )
Fine-tune on custom dataset
model . train ( data = "custom_dataset.yaml" , epochs = 100 , imgsz = 640 , batch = 16 )
Inference
results
model . predict ( source = "image.jpg" , conf = 0.5 ) for result in results : boxes = result . boxes for box in boxes : xyxy = box . xyxy [ 0 ] . tolist ( )
Bounding box
conf
box . conf [ 0 ] . item ( )
Confidence
cls
box . cls [ 0 ] . item ( )
Class ID
print ( f"Detected { cls } at { xyxy } with confidence { conf } " ) Segment Anything (SAM) Universal segmentation: from segment_anything import sam_model_registry , SamPredictor
Load SAM
sam
sam_model_registry [ "vit_h" ] ( checkpoint = "sam_vit_h.pth" ) predictor = SamPredictor ( sam )
Set image
predictor . set_image ( image )
Segment with point prompt
masks , scores , logits = predictor . predict ( point_coords = np . array ( [ [ 500 , 375 ] ] ) ,
Click point
point_labels
np . array ( [ 1 ] ) ,
1 = foreground
multimask_output
True )
Segment with box prompt
masks , scores , logits = predictor . predict ( box = np . array ( [ x1 , y1 , x2 , y2 ] ) ) Model Optimization Pipeline Prepare models for production: def optimize_for_deployment ( model , sample_input ) :
Step 1: Export to ONNX
torch . onnx . export ( model , sample_input , "model.onnx" , opset_version = 13 , dynamic_axes = { "input" : { 0 : "batch" } } )
Step 2: Quantize (INT8)
from onnxruntime . quantization import quantize_dynamic quantize_dynamic ( "model.onnx" , "model_quantized.onnx" , weight_type = QuantType . QInt8 )
Step 3: Benchmark
import onnxruntime as ort session = ort . InferenceSession ( "model_quantized.onnx" ) benchmark_inference ( session , sample_input ) return "model_quantized.onnx" Common Pitfalls to Avoid Training from scratch when transfer learning would work Not augmenting data appropriately for the task Data leakage through improper train/test splits Ignoring class imbalance in training data Overfitting to training data without regularization Not testing on diverse, real-world images Deploying without latency and throughput testing Assuming models work on all image types without testing