Section outline

  • In this lesson, you'll reuse the image “01_On-Gossamer-Wings.jpg.” You downloaded this image to your device/computer in activity 2.1. If you need to download the image again, you can do so in this activity. Click on the Resources tab and choose "01_On-Gossamer-Wings2.jpg".
    ::在此课程中, 您将重新使用图像“ 01_ on- Gossamer- Wings.jpg ” 。 您在活动 2. 1 中将此图像下载到设备/ 计算机 。 如果您需要再次下载图像, 您可以在此活动中这样做 。 点击资源标签并选择“ 01_ on- Gossamer- Wings2. jpg ” 。


    Photo images are composed of little dots called pixels (px), and image size is measured in pixel dimensions. For example, an image that measures 2949 x 2540 pixels has more pixels than an image that measures 517 x 600 pixels. 2949 x 2540 = 7,490,460 (7.5 megapixels), while 517 x 600 = 310,200 (0.3 megapixels). What image size is the best depends on how you will be using an image. The 7.5 megapixel image has a file size of 2.6 megabytes and is great for printing on a photo printer but pretty large for attaching to an email or adding to a presentation, like PowerPoint. The 0.3 megapixel image would work well for screen display in PowerPoint or dragged smaller on a word processing document, like Word, but would look blocky/pixelated if printed on a printer.
    ::照片由小点组成,称为像素(px),图像大小用像素尺寸测量。例如,一个测量 2949 x 2540 像素的图像比测量 517 x 600 像素. 2949 x 2540 = 7,490,460 (7.5 兆像素) 的图像多。而517 x 600 = 310,200 (0.3 兆像素) 的图像大小最取决于您如何使用图像。7.5 兆像素图像的文件大小为2.6兆字节,非常适合在照片打印机上打印,但对于附在电子邮件上或添加演示文稿来说则非常大。 0. 3 兆像素图像对于在 PowerPoint 显示屏幕或拖小于单词处理文档(如Word)的屏幕来说效果良好,但如果打印在打印机上打印,则会看到块状/像素。


    Open the image "01_On-Gossamer-Wings.jpg" in Pixlr Editor. Notice at the bottom left of the  Image  panel that you are viewing the 2540 x 2949 pixel image at 27% of full size. This is because the computer screen can only display 72 pixels per inch. To see the image at full size would require a monitor over 35 inches wide and almost 41 inches tall. In this activity, we’ll resize the image for screen display. Note: dragging the image smaller on a document or on the computer screen doesn’t change the pixel dimensions or reduce the image’s file size. It just makes the image look smaller.
    ::打开 Pixlr 编辑器中的图像“01_On-Gossamer-Wings.jpg ” 。 在图像面板左下端请注意,您正在全尺寸27 % 的 2540 x 2949 像素图像中查看 2540 x 2949 像素图像。 这是因为计算机屏幕只能显示每英寸72 像素。 要全尺寸看到图像, 需要超过 35 英寸宽, 近41 英寸高的监视器。 在此活动中, 我们将调整屏幕显示图像的大小 。 注意: 在文档或计算机屏幕上拖动较小图像不会改变像素尺寸或缩小图像的文件大小。 它只会让图像看起来更小一些 。

    This 2540 x 2949 version of the image is good for high quality printing, but the pixel dimensions are not needed for screen display.
    ::此图像的 2540 x 2949 版本有利于高质量的打印, 但屏幕显示不需要像素尺寸 。

    On Gossamer Wings


     

    1. To resize the actual pixel dimensions in Pixler Editor, click on the  Image  menu and choose  Image size .
      ::要调整像素编辑器中的实际像素尺寸,请单击图像菜单并选择图像大小。
    2. Make sure that  Constrain proportions  is checked so that changing either the width or height allows the editor to change the other dimension proportionately.
      ::确保检查 Constrain 比例, 以便修改宽度或高度, 使编辑能够按比例更改其他维度 。
    3. Next, change the height to 600 pixels (the width will change to 517 pixels).
      ::接下来,将高度改为600像素(宽度将改为517像素)。
    4. Then, click the  OK  button. The image in the editor will shrink because you’ve decreased the pixel dimensions.  Because there are fewer pixels in the resized image, Pixlr Editor actually reconstructs the image to look as close to the original as possible.
      ::然后单击“确定”按钮。编辑器中的图像会缩小,因为您已经降低了像素尺寸。由于调整后的图像中像素较少,像素编辑器实际上将图像重塑为尽可能接近原始图像。
    5. Drag the  Image  panel larger and change the viewing percent to 100%.
      ::将图像面板拖大,并将视图百分比修改为100%。

    image resizing


    The new 517 x 600  image looks the same  as the  2540 x 2949 version  on the screen display. There is a difference, however. While the new image size is good for screen display, there are too few pixels for high quality printing.
    ::新的 517 x 600 图像看起来与屏幕显示中的 2540 x 2949 版本相同 。 但有不同 。 虽然新的图像大小适合屏幕显示, 但用于高质量打印的像素太少 。

    On Gossamer Wings


    RECORD YOUR FINDINGS
    ::记录你的调查结果

    • What is a pixel?
      ::象素是什么?
    • How are megapixels calculated?
      ::如何计算巨型像素 ?
    • When would you want an image with more megapixels? Fewer megapixels?
      ::您什么时候想要更多巨型像素的图像? 更少的巨型像素 ?
    • What are the steps for resizing pixel dimensions in Pixlr Editor?
      ::在像素编辑器中调整像素尺寸的步骤是什么 ?