O tamanho das imagens importa para um site? - @Curso em Vídeo HTML5 e CSS3

Understanding Image Formats and Sizes

Introduction to Image Formats

• The lesson begins with a recap of image formats discussed in the previous class, specifically JPG and PNG, highlighting their advantages and disadvantages.

• The instructor emphasizes the importance of understanding image sizes as they prepare to incorporate images into websites.

Importance of Generating Own Images

• Students are encouraged to create their own images rather than relying on pre-made ones, which is essential for web development.

Inspirational Story: Rafael Silva

• A story about Rafael Silva from Rio de Janeiro is shared, who participated in a Record initiative aimed at preparing individuals for the job market.

• Rafael's journey culminated in his employment at a major national bank after completing a development program.

Technical Aspects of Image Handling

• The instructor discusses how large image files can distort when resized improperly, using an example of a large JPG file that shows compression artifacts.

• It’s noted that while JPG files look good, they may not provide perfect quality; larger files can lead to slower website performance.

Practical Steps for Managing Images

• The instructor plans to demonstrate how to generate various sizes of images and explains the significance of file size management in daily tasks.

• A new folder named "images" is created for organization purposes before proceeding with image manipulation.

Renaming and Resizing Images

• Instructions are given on renaming files within Windows by right-clicking or clicking twice on the filename.

• An example image named "paisagem full" (full landscape), weighing 1.8 MB, is identified as too heavy for web use.

Using Software Tools for Image Editing

• The instructor opens an editing program previously installed to work on resizing the large image file effectively.

Resizing Process Explained

• Details about the current dimensions (3375 x 2250 pixels) are provided; it’s suggested that optimal width should be around 1500 pixels for web usage.

Image Resizing and Exporting Techniques

Understanding Image Dimensions and Resolution

• The speaker discusses adjusting the image width to 1,500 pixels while maintaining a reasonable resolution of 72 DPI, suggesting that higher resolutions (100, 150, or 200) can also be used without issues.

• After resizing the image, it is noted that viewing at 50% shows a smaller version; switching to 100% reveals the original size of over 1,500 pixels.

• The speaker plans to resize the image again to dimensions of 1,200 pixels with a resolution of 50 DPI for optimal use.

Exporting Images Without Overwriting Originals

• Emphasis is placed on not overwriting original images; it's recommended to keep full-size versions in backup for future needs.

• When exporting as JPEG, the quality setting is adjusted to around 70%, which significantly reduces file size while maintaining acceptable quality.

• The export process successfully creates a new version while retaining the original high-resolution file.

Further Resizing for Web Use

• A subsequent resizing step targets dimensions suitable for web content (600x650), ensuring images are appropriately sized for their intended use.

• Another export occurs at this new size with similar quality settings; this results in manageable file sizes ideal for website integration.

Importance of File Size Management

• The speaker highlights how reducing image sizes from larger files (e.g., from nearly 2 MB down to about 300 KB or less) improves website performance and loading times.

• It’s reiterated that keeping full-sized images allows flexibility if clients request changes or higher-quality outputs later.

Working with PNG Files

• Transitioning to working with PNG files involves opening them in GIMP; transparency features are noted as important when handling logos or graphics.

• The necessity of resizing large logos (e.g., Faetec logo at over 1,187 pixels wide) is discussed due to potential impacts on website speed and efficiency.

Final Considerations on Image Quality and Website Performance

• Recommendations include generating smaller files (e.g., widths around 400 pixels), balancing between quality and performance since larger files can slow down websites significantly.

Image Exporting and Compression Techniques

Understanding Image Dimensions and Formats

• The speaker discusses exporting an image with a width of 400 pixels, noting that the software does not prompt for transparency settings like Photoshop does.

• Mention of PNG compression levels; the speaker emphasizes maintaining transparency during export while resizing images for different uses, such as logos on websites.

Resizing Images for Web Use

• The process of resizing an image to 200 pixels is demonstrated, with the speaker planning to save it under a new name (Faetec 200).

• A comparison is made between file sizes: a full-size image at 400 pixels is 17 KB, while the resized version at 200 pixels is only 13 KB. This highlights how even small differences in size can impact website performance.

Importance of Image Size in Web Traffic

• The speaker explains that reducing image size from 23 KB to 13 KB can significantly affect load times when dealing with high traffic (over one million visits), emphasizing efficiency in web design.

Utilizing Free Software for Image Editing

• The discussion shifts to using free software for image editing without legal concerns, highlighting its capabilities similar to paid options like Photoshop.

Course Promotion and Community Engagement

• The speaker invites viewers to contribute artwork for course promotion, providing an email address for submissions and encouraging artists to create designs based on specified dimensions.

• Emphasis on community involvement where selected artworks will be shared on social media platforms, fostering collaboration among participants.

Conclusion and Next Steps