@data-min-scale : The Minimum Scaling Factor Attribute

The data-min-scale attribute specifies the minimum scaling factor for image elements when they are automatically resized to fit within their container. It prevents images from being scaled down too much, maintaining a minimum readable or visible size in PDF documents.

Usage

The data-min-scale attribute is used with <img> elements to:

Set a minimum scale limit for automatic image resizing
Prevent images from becoming too small
Maintain image legibility and visibility
Control image scaling behavior in constrained spaces
Ensure minimum quality standards for scaled images

<!-- Image will not scale below 50% of original size -->
<img src="large-diagram.png" data-min-scale="0.5" style="max-width: 100%;" />

Supported Elements

The data-min-scale attribute is supported by:

Element	Description
`<img>`	Image element

Attribute Values

Syntax

<img src="image.jpg" data-min-scale="factor" />

Value Type

Type	Range	Description	Example
Decimal	0.0 - 1.0	Minimum scale as fraction of original	`data-min-scale="0.5"` = 50% minimum
Percentage	1% - 100%	Minimum scale as percentage	`data-min-scale="0.75"` = 75% minimum

Common Values

Value	Meaning	Use Case
`1.0`	No scaling down allowed	Preserve original size always
`0.75`	Minimum 75% of original	Slight scaling allowed
`0.5`	Minimum 50% of original	Moderate scaling allowed
`0.25`	Minimum 25% of original	Significant scaling allowed
`0.1`	Minimum 10% of original	Maximum flexibility

Default Behavior

If data-min-scale is not specified:

Images can scale down to fit available space without limit
Very small images may result if container is narrow
No minimum size constraint is applied

Binding Values

The data-min-scale attribute supports data binding:

Static Minimum Scale

<img src="diagram.png" data-min-scale="0.6" style="max-width: 100%;" />

Dynamic Minimum Scale

<!-- Model: { minImageScale: 0.5 } -->
<img src="chart.png" data-min-scale="" />

Conditional Scaling

<!-- Model: { allowSmallImages: false } -->
<img src="photo.jpg"
     data-min-scale="" />

Notes

Scaling Behavior

When an image is placed in a container:

Image tries to fit within available space
If image is larger, it scales down
Scaling stops at data-min-scale limit
If minimum scale is reached and image still doesn’t fit, it may overflow or clip

Aspect Ratio Preservation

The data-min-scale works alongside aspect ratio constraints:

Images maintain their aspect ratio while scaling
The minimum scale applies to both dimensions proportionally
Width and height scale together

Use Cases

Maintain Readability:

<!-- Diagram with text that must remain readable -->
<img src="flowchart.png" data-min-scale="0.7" />

Quality Control:

<!-- Photo that shouldn't be too pixelated -->
<img src="product-photo.jpg" data-min-scale="0.5" />

Technical Diagrams:

<!-- Technical drawing with fine details -->
<img src="technical-drawing.svg" data-min-scale="0.8" />

Interaction with CSS Sizing

The data-min-scale works with CSS properties:

<!-- CSS max-width limits container size -->
<!-- data-min-scale limits how small image can get -->
<img src="large-image.png"
     style="max-width: 100%; height: auto;"
     data-min-scale="0.6" />

Container Constraints

If container is too small and minimum scale is reached:

Image may overflow the container
Consider using overflow: hidden on container
Or adjust layout to accommodate minimum size

PDF-Specific Considerations

In PDF generation:

Image scaling affects file size and quality
Smaller scales may reduce clarity
Minimum scale ensures acceptable quality
Balance between size constraints and quality needs

Examples

Example 1: Basic Minimum Scale

<!-- Image will not scale below 60% of original size -->
<div style="width: 300pt;">
    <img src="large-diagram.png"
         data-min-scale="0.6"
         style="max-width: 100%; height: auto;" />
</div>

Example 2: Technical Diagram Protection

<!-- Ensure technical details remain visible -->
<div class="diagram-container" style="max-width: 500pt;">
    <img src="architecture-diagram.svg"
         alt="System Architecture"
         data-min-scale="0.75"
         style="width: 100%; height: auto;" />
    <p style="font-size: 9pt; text-align: center;">
        Figure 1: System Architecture Overview
    </p>
</div>

Example 3: Product Photos

<!-- Don't let product images get too small -->
<div style="width: 200pt; height: 200pt; overflow: hidden;">
    <img src="product-image.jpg"
         alt="Product Photo"
         data-min-scale="0.5"
         style="width: 100%; height: auto;" />
</div>

Example 4: Report with Charts

<h2>Quarterly Sales Performance</h2>

<div style="width: 400pt; text-align: center;">
    <img src="sales-chart-q4.png"
         alt="Q4 Sales Chart"
         data-min-scale="0.7"
         style="max-width: 100%;" />
    <p style="font-size: 10pt; margin-top: 10pt;">
        Figure 2.1: Q4 Sales by Region
    </p>
</div>

Example 5: Multiple Images with Different Scales

<div style="display: grid; grid-template-columns: 1fr 1fr; gap: 20pt;">
    <!-- Logo: never scale down -->
    <div>
        <img src="company-logo.png"
             data-min-scale="1.0"
             style="width: 100%;" />
    </div>

    <!-- Photo: can scale more -->
    <div>
        <img src="team-photo.jpg"
             data-min-scale="0.4"
             style="width: 100%;" />
    </div>
</div>

Example 6: Responsive Image Sizing

<!-- Large screen: full size -->
<!-- Small container: scales down but not below 65% -->
<img src="infographic.png"
     alt="Data Infographic"
     data-min-scale="0.65"
     style="max-width: 100%; height: auto;
            border: 1pt solid #ddd; padding: 10pt;" />

Example 7: Data-Bound Image Scaling

<!-- Model: { images: [{src: "...", minScale: 0.5}, ...] } -->

<template data-bind="">
    <div style="margin-bottom: 20pt;">
        <img src=""
             data-min-scale=""
             style="max-width: 100%;" />
    </div>
</template>

Example 8: Scientific Figures

<div class="figure" style="page-break-inside: avoid;">
    <div style="width: 500pt; margin: 0 auto;">
        <img src="experiment-results.png"
             alt="Experiment Results"
             data-min-scale="0.8"
             style="width: 100%; border: 1pt solid #333;" />
    </div>
    <p style="text-align: center; font-style: italic; margin-top: 10pt;">
        Figure 3: Experimental results showing temperature correlation
    </p>
</div>

Example 9: Invoice with Logo

<div style="display: flex; justify-content: space-between; margin-bottom: 30pt;">
    <!-- Company logo must remain readable -->
    <div style="width: 150pt;">
        <img src="company-logo.svg"
             alt="Company Logo"
             data-min-scale="0.9"
             style="width: 100%;" />
    </div>

    <div style="text-align: right;">
        <h1 style="margin: 0;">INVOICE</h1>
        <p>Invoice #: INV-2024-001</p>
    </div>
</div>

Example 10: Technical Manual with Detailed Diagrams

<h2>3. Installation Steps</h2>

<div style="margin: 20pt 0;">
    <h3>Step 1: Connect Components</h3>
    <img src="step1-diagram.png"
         alt="Step 1 Connection Diagram"
         data-min-scale="0.75"
         style="max-width: 100%; border: 2pt solid #336699; padding: 10pt;" />
</div>

<div style="margin: 20pt 0;">
    <h3>Step 2: Configure Settings</h3>
    <img src="step2-screenshot.png"
         alt="Step 2 Configuration Screen"
         data-min-scale="0.7"
         style="max-width: 100%; border: 2pt solid #336699; padding: 10pt;" />
</div>

Example 11: Image Gallery with Minimum Sizes

<h2>Product Gallery</h2>

<div style="display: grid; grid-template-columns: repeat(3, 1fr); gap: 15pt;">
    <div style="border: 1pt solid #ddd; padding: 10pt;">
        <img src="product1.jpg" data-min-scale="0.5" style="width: 100%;" />
        <p style="text-align: center; margin-top: 5pt;">Product A</p>
    </div>

    <div style="border: 1pt solid #ddd; padding: 10pt;">
        <img src="product2.jpg" data-min-scale="0.5" style="width: 100%;" />
        <p style="text-align: center; margin-top: 5pt;">Product B</p>
    </div>

    <div style="border: 1pt solid #ddd; padding: 10pt;">
        <img src="product3.jpg" data-min-scale="0.5" style="width: 100%;" />
        <p style="text-align: center; margin-top: 5pt;">Product C</p>
    </div>
</div>

Example 12: Certificate with Seal

<div style="text-align: center; padding: 40pt; border: 5pt double #336699;">
    <h1 style="font-size: 32pt;">Certificate of Achievement</h1>

    <p style="margin: 20pt 0;">This certifies that</p>
    <h2 style="font-size: 24pt; color: #336699;">John Doe</h2>

    <p style="margin: 20pt 0;">has completed the course</p>

    <!-- Official seal must remain visible -->
    <div style="margin: 30pt auto; width: 100pt;">
        <img src="official-seal.png"
             alt="Official Seal"
             data-min-scale="0.95"
             style="width: 100%;" />
    </div>

    <p style="font-size: 11pt;">Date: January 15, 2024</p>
</div>

Example 13: Dashboard with Metric Visualizations

<h1>Performance Dashboard</h1>

<div style="display: grid; grid-template-columns: 1fr 1fr; gap: 20pt;">
    <!-- Revenue chart -->
    <div style="padding: 15pt; border: 1pt solid #ddd;">
        <h3>Revenue Trend</h3>
        <img src="revenue-chart.png"
             data-min-scale="0.6"
             style="width: 100%;" />
    </div>

    <!-- Growth chart -->
    <div style="padding: 15pt; border: 1pt solid #ddd;">
        <h3>Growth Rate</h3>
        <img src="growth-chart.png"
             data-min-scale="0.6"
             style="width: 100%;" />
    </div>

    <!-- User chart -->
    <div style="padding: 15pt; border: 1pt solid #ddd;">
        <h3>Active Users</h3>
        <img src="users-chart.png"
             data-min-scale="0.6"
             style="width: 100%;" />
    </div>

    <!-- Conversion chart -->
    <div style="padding: 15pt; border: 1pt solid #ddd;">
        <h3>Conversion Rate</h3>
        <img src="conversion-chart.png"
             data-min-scale="0.6"
             style="width: 100%;" />
    </div>
</div>

Example 14: Conditional Minimum Scale Based on Image Type

<!-- Model: { images: [{src: "...", type: "diagram|photo", ...}] } -->

<template data-bind="">
    <div style="margin-bottom: 20pt;">
        <!-- Diagrams need higher minimum scale than photos -->
        <img src=""
             alt=""
             data-min-scale=""
             style="max-width: 100%; border: 1pt solid #ddd; padding: 10pt;" />
        <p style="text-align: center; font-size: 10pt; margin-top: 5pt;">
            
        </p>
    </div>
</template>

Example 15: Complex Report with Multiple Image Types

<h1>Annual Report 2024</h1>

<!-- Company logo header -->
<div style="margin-bottom: 30pt;">
    <img src="company-logo.svg"
         alt="Company Logo"
         data-min-scale="1.0"
         style="width: 200pt;" />
</div>

<!-- Executive summary chart -->
<h2>Executive Summary</h2>
<div style="width: 500pt; margin: 20pt 0;">
    <img src="summary-metrics.png"
         alt="Key Metrics"
         data-min-scale="0.7"
         style="width: 100%;" />
</div>

<!-- Financial charts -->
<h2>Financial Performance</h2>
<div style="display: grid; grid-template-columns: 1fr 1fr; gap: 20pt;">
    <div>
        <h3>Revenue</h3>
        <img src="revenue-breakdown.png"
             data-min-scale="0.65"
             style="width: 100%;" />
    </div>
    <div>
        <h3>Profit Margins</h3>
        <img src="profit-margins.png"
             data-min-scale="0.65"
             style="width: 100%;" />
    </div>
</div>

<!-- Team photos -->
<h2>Leadership Team</h2>
<div style="display: grid; grid-template-columns: repeat(4, 1fr); gap: 15pt;">
    <div>
        <img src="ceo-photo.jpg" data-min-scale="0.4" style="width: 100%;" />
        <p style="text-align: center; font-size: 9pt;">CEO</p>
    </div>
    <div>
        <img src="cfo-photo.jpg" data-min-scale="0.4" style="width: 100%;" />
        <p style="text-align: center; font-size: 9pt;">CFO</p>
    </div>
    <div>
        <img src="cto-photo.jpg" data-min-scale="0.4" style="width: 100%;" />
        <p style="text-align: center; font-size: 9pt;">CTO</p>
    </div>
    <div>
        <img src="coo-photo.jpg" data-min-scale="0.4" style="width: 100%;" />
        <p style="text-align: center; font-size: 9pt;">COO</p>
    </div>
</div>

<!-- Technical architecture diagram -->
<h2>Technology Infrastructure</h2>
<div style="page-break-inside: avoid; margin: 20pt 0;">
    <img src="architecture-diagram.svg"
         alt="System Architecture"
         data-min-scale="0.8"
         style="width: 100%; border: 2pt solid #336699; padding: 15pt;" />
    <p style="text-align: center; font-style: italic; margin-top: 10pt;">
        Figure 5.1: Complete system architecture showing all components and integrations
    </p>
</div>