Image file formats often used
File formats File size Viewed by Other
BMP big; no compression MS Paint or other accepts clipboard copied image
JPG for internet and archiving web browser or other makes small files of photos
GIF good for internet, tables, etc. web browser or other for images with few shades
WMF good for clip art CDs choose a viewer previewing clip art is a challenge
Functions often provided by a typical image viewer/converter
Allows the user to alter the format used for an image. Most viewers will provide for modifying images.
Modifications can include:
Cropping enclosing the image within a smaller rectangular size by removing margin content
Re-scaling altering the scale factor of the image (i.e., stretching or shrinking)
Modifying the quality brightness, contrast, gamma factor, color balance, altering image content
In addition, it may provide features for convenient printing
Some image application programs that can do image modification
MS Paint, Visua, Irfan View, Adobe Photo Deluxe and Paint Shop Pro will be mentioned here. This group has been cited because they are often found among the software available to users.
MS Paint is installed with Windows. It can be used for cropping and re-sizing, among others. Irfan View is a free download. Visua can be obtained from private archives and is mainly an easy-to-operate viewer and format converter, which can be used to crop and re-size. Irfan View is full-featured viewer/modifier/converter. Adobe Photo Deluxe is often bundled with purchased peripherals like printer, scanner, or camera. It is a full-featured viewer/modifier/converter. More complete image application programs like Adobe PhotoShop LE have occasionally been sent as free software with the purchase of a peripheral. JASCs Paint Shop Pro has many uses, and is suitable for colorizing and some types of retouching. It also is an image format converter, with the standard supported file types. It has a collection of tools that allow a user to make many types of midifications to an image. In the Colors|Adjust tool, there are six menu choices that provide dialog screens for making modifications. Among them are a gamma tool adjustment where the gamma values selected for red, green , and blue may be selected independently or together.
Altering the image content (in addition to the modifying steps shown above) can include:
Smoothing edges, reducing granularity, reducing moiré patterns, adding special effects, balancing brightness from one region of the image to another, retouching, rotating the image by multiples of 90 degrees, rotating the image by a selected amount, and flipping an image horzontally or vertically.
Printing features may include:
Print preview, an image scaling and positioning feature, rotating the image by 90 degrees, presence or absence of header, footer, pre-set margins, etc.
Viewing features may include:
Manual or automatic stepping through a collection of files, viewing a cluster of files as thumbnails, reproducing sound files along with images
Applications to add displayability to images include:
Adding captions and/or legends, adding automatic presentation features to an image collection
Displaying animated images:
Animated GIFs are a stepped sequence of GIF images which simulate motion. Animated GIFs wont work in all viewing software. They are commonly used on web pages, as they will display properly in web browsing viewers.
A brief discussion on images which are produced in scanner formats
or in image converter formats.
When working with images in scanner software or in image converter software, it is useful to remember that these are temporary image files with formats which:
Can modify the appearance of the image file that was imported
Can be used to make a print of the modified image
Usually wont be useful in this current format to share but will allow you to see what you have
Must be saved or exported to a folder elsewhere on a drive which has a folder assigned to accept it, if you wish to share it or archive it
Dont alter the source image that is, not unless you save or export the file and assign the same file name and place it in the folder from which it came
Although such scanned temporary files may be retained by some scanner software, they will only serve as your own archived images for later retrieval, and then generally for short retention periods
A discussion of image resolution
Resolution is a term that expresses how well the graphic presentation shows the spatial details in a picture. It is a measure of the fineness of the picture elements.
Digital images consist of a large number of picture elements (pixels) in rows and columns, each with a defined color. A pixel is one of many cells that form a picture. An image may extend X pixels from left to right and Y pixels from top to bottom, and contain X times Y pixels. A user has some latitude in how many pixels are used to display a certain picture. For example, the monitor has a few settings for selecting the full screen presentation. The most commonly used resolution setting is 800 X 600 pixels. If every pixel is actually seen (including the corners of the image), there will be 480,000 of them.
Modern digital cameras have frame sizes of 2 megapixels or 4 megapixels, so the need to re-size and crop these images becomes important. If a full-frame image is received as an attachment, the recipient may see only the upper-left corner of the image unless they do some scrolling. Then they may like to make the picture small enough so that it is more readily viewable without scrolling. Re-sizing and cropping are topics discussed later.
Most viewing software applications (and printers) display the typical image formats BMP, JPG, and GIF at 96 pixels per lineal inch. If a user wishes to stretch a given image file for presentation or for printing, they will get no better resolution by zooming in to make the image bigger.
If an image file is modified by stretching or shrinking the overall dimensions, the software must find a means for making the picture information accommodate a newly formed matrix of pixel sizes or pixel count. If the pixel count changes, the picture must retain its basic character, yet the color assignments of the new set of pixels is not the same as the original picture. The software must have algorithms that account for these requirements. The ability of software to accommodate these zoom requirements varies from one software package to another.
A test of the quality of image-modifying software is to note if there is significant degradation of an image if it undergoes a series of changes.
One of the more noticeable degradations due to zooming will appear in the quality of the text. A particular font type and size will have specific pixel cells blackened. If you depart from the resolution in which the text was acquired, some software will have a tough time keeping the boundaries between black and white organized so the stroke width and precise shape of the text characters are maintained or simulated..
A zoom-type feature may be used in the MS Paint application by commanding Image|Stretch/Skew. When the Stretch and Skew dialog box appears, you will note that there are small highlighted windows opposite the words Horizontal and Vertical in the upper (Stretch) panel which each say 100. To shrink the picture to half of the original image dimensions, you do so in two steps. First, click (dropping a cursor) in the Horizontal (small) window, and replace the 100 with 50 , and click on Okay. Then do the same for the 100 value in the Vertical (small) window, and click on Okay.
Scanner software generally has choices of scan resolution, as well as black and white vs. color, and a further determination of gray scale or simply black OR white coding when choosing black and white. The latter distinction is important when choosing whether you need two levels (one bit) of gray (either black OR white) or many levels (gray scale), which affords a more accurate rendition of the source material.
Most often, you will find that the scanner software offers about five default settings for making these selections, and the means for making custom settings which depart from the default values.
A large picture will produce a large image file, and settings that provide more picture details will make that file even bigger. The temporary image format used in scanner software and in image conversion software has no compression (i.e., all picture information is defined within each presented pixel). Thus, the user should note that it takes time for a slow computer to compile all the necessary data to form and to reformat this image if an unusually large, detailed image is being used. In fact, users should be aware that limitations of computer processing speed may not be apparent until you use large media files like a large color photos with high resolution.
A user should be judicious in the choice of the scanner settings to make an image file having suitable spatial resolution and color resolution (the fineness of allowed step changes in the color palette) so that the selected resources are appropriate for the end result.
Another image format is available that provides for more than 96 dpi resolution. Although the scanner software can accommodate resolutions that exceed 300 dpi, the user may wish to transfer that file to another computer which doesnt have the same scanner software. The format most often used for this purpose is TIF or TIFF. The TIF format provides for resolutions of 300 dpi, or other values which may be set when encoding the file. Also, it will encode either as uncompressed or compressed (JPG and LZW are compression options).
The software application needed for creating a TIF file is (Kodak) Imaging, which is automatically installed with modern versions of Windows. Like MS Paint, Imaging will accept images from a clipboard, but you must define the spatial resolution and the color depth unless you are willing to accept the default settings. Imaging can be used for pictures of higher resolution than MS Paint, as it supports spatial resolutions greater than 96 dpi.
A user can copy or export scanned high-resolution images to JPG , GIF, or BMP formats, but the picture dimensions will increase to match the defined 96 dpi for these formats. If images are exported into TIFF format in Imaging with a resolution that matches that of the image exported from the scanner software, the dimensions wont change.
The JPG and GIF formats have become standards for use on the internet, as they are able to reduce file sizes while preserving picture details. This is accomplished with the use of sophisticated algorithms that make choices about the picture elements (pixels) whose color definition dont change from the one which precedes it in the defined sequence of forming the pixels into the file. In this sense, the algorithm votes out the data associated with certain pixels if there is no change from its preceding neighbor. In the viewer software, its algorithm has the ability to reformulate the original image in the absence of the data for those pixels whose color data was voted out. Also, web browsers will present files in JPG and GIF formats, while many web browsers may not present some of the other formats.
JPG file creation depends on a quality selection, often made by the user, in which the user makes a trade-off between the requirements for retaining image quality, and the resultant file size. Thus, a user can make a file with less than 100 quality retention if a smaller file size is desired. A JPG file is most often selected if the picture contains subtle shadings of color, and a small file size is desired. A JPG quality factor of 70 is often acceptable, as it represents a good trade-off between picture quality and file size. A GIF file is often chosen for tables, figures, cartoons, clip art, etc., where few shades of color are present. Choosing the GIF format for this kind of picture often results in a smaller file than a JPG file would provide.
GIF is often used for the collection of small image insets which are placed on a web page. If a GIF file of appreciable dimension is shown in the top half of a web home page (so a visitor will see the image form on their screen), the visitor may notice that this image forms in a way which may seem distracting, since the picture elements form in cells much bigger than a single pixel, and these cells become progressively smaller as the fully resolved image takes form. This effect usually is not noted in GIF files of small dimension.
Screen image capture
You may find it convenient to capture the image content that is presented on your monitor screen. It is an easy matter to Copy this image data on the virtual clipboard which is provided by Windows. To copy this data to the clipboard, simply press Alt + Pnrt Scrn (both keys at the same time). This will place data on the clipboard just as the Copy feature does with highlighted data in text transfer applications. The next step is to find a place to Paste this image data. This is often done by opening MS Paint and commanding Edit|Paste, at which point the image appears in the Paint application screen. Then you can perform some steps on the image like cropping and saving the image. Note that a few other image programs like Irfan View will also accept importing the image by the use of the Paste command.
One of the unique features about MS Paint is its ability to accept a word file that is on the clipboard. Thus, a user can Copy all or part of a page from MS Word (which may contain images) and Paste it directly into MS Paint. This information may be helpful for those who would find it difficult to capture as much height from the document page as would otherwise be available by doing a screen capture. This will be described in more detail below.
A user should be advised that if they want to preserve image quality, they should prefer using screen capture over Copying from the Word application. In order to screen capture of the entire height of the layout on a given page in the Portrait orientation, they may have to use a zoom feature of their screen presentation. The zoom feature mentioned here is that of using the Desktop|Properties to reset the screen resolution up to 1280 X1024 pixels. This will usually provide enough height for the screen to show all the text (about 10 inches), when View|Full Screen presentation is used. This is desribed in more detail below. Full Screen is a feature that remove the display of most of the toolbars at top and/bottom that wouold otherwise limit sowing the entire layout height on the screen. Also note that the zoom feature of Word should be set for 100 if you want the image to be normal size. When you obtain image data by means of a screen capture it can be pasted into Irfan View as well as MS Word. Generally, a user will want to crop away extraneous border elements obtained from a screen view capture.
Note also that MS Word has an exceptionally good Zoom capability that tends NOT to compromise the presentation of text or images as you depart from the original size.
When using the Copy feature in MS Word, there will be no need to crop away margins, as the Copy feature does that automatically. The user whould also be aware that the https://www.tradebit.com template in MS Word must be set at least as large as demanded by the page layout if not, some of the layout will be truncated.
Also, note the following: a greater amount of effective screen area for doing a screen capture is provided by re-setting the screen display for a larger number of pixels. This is done by going to the desktop, right-clicking on the background, clicking on the Properties on the drop-down menu, clicking on Settings tab on the pop-up screen, and moving the slider in the Screen area panel to the right. When the desired pixel setting is obtained, click on Okay on the Settings screen, then on Okay in the Display Properties dialog box, then click on Yes in the Monitor setting dialog box. By doing this, the screen displays more copy, and more data is contained on the clipboard after doing a screen capture, with little loss of image detail. And you should be aware of the zoom setting of the file displayed on the screen prior to the screen capture. In some cases, the zoom value will default to a value less than 100, as Word has some features for ensuring that the width of displayed text will fit within the width of the displayable area of the screen.
Some observations on the rectangular boundary around an image in MS Paint. The size of the active screen prior to pasting image data is defined by a white rectangle. It is preferable that this be smaller than the area of the image to be pasted, as this area will expand to accommodate the size required when you say its okay to paste it into Paint even if the area is too small. Next, it is best to remove the defaulted dashed line that initially surrounds the pasted image. This can be done by commanding SaveAs, and you can defer naming the file if you choose. If the dashed lines arent removed, your image dimensions will become proportioanlly smaller when you pull in the picture edges while cropping the picture. Also, if you want to move out the image boundary, allowing a non-cropped white margin, you can do that by dragging the little black dot outward.
A simpler method for placing a page of formatted text from an MS Word application is available. The layout content will be placed on the clipboard by highlighting the material, then Copying it to place it on the clipboard. Note that up to one page of MS Word layout can be captured, but it must fall within the boundary of the template defined in https://www.tradebit.com, a template file which resides in C:WindowsApplication DataMicrosoftTemplates. This is the file that retains information on the margin settings each time MS Word is opened and is ready to accept the creation of a new document. The default margins can most easily be reset in the Page Setup|Margins dialog box in Word by clicking on the Default button and then clicking on Yes when the new margin settings have been established.
To crop the image, you must first remove the dashed lines along the edge of the image. This can be done by commanding a Save As, at which point you can pick a folder and a file name for the image to be saved in. To crop, you must find the small black dots along middle of the lower and right sides of the image. By placing the mouse pointer on top of one of these dots until you see a double-headed arrow, then you can drag in the edge of the picture until the desired margin is established. To crop the other two sides, command an Image|Flip/Rotate|Rotate by angle|180 degrees, which will invert the image. Then you do the same steps to pull in the edges of the image which are now the lower and right edges. When satisfied, invert the image again by doing Image|Flip/Rotate|Rotate by angle|180 degrees, and command a Save on the modified image.
You may note that when the mouse pointer is within the boundary of the image, two coordinate numbers appear near the lower right corner of the image boundary. These numbers correspond to the X and Y coordinates at that point, measured in pixels from the upper left corner of the image. The upper left pixel has the coordinates 0,0. If you are bringing in the right or the lower boundary by dragging on the tiny black dot at the mid-point of these boundaries, the coordinate of that boundary will represent the number of lineal pixels retained in that temporary image. Thus if you want to crop an image to a precise size, MS Paint provides the tools to do so.
Notes on cropping
Means for cropping will be described for MS Paint, and later, for Irfan View, and for Adobe image applications. To import a JPG file into MSPaint, click on Edit in the menu bar, then on Paste from in the drop-down menu. In the Paste From dialog box, select JPG for the data in the slot beside Files of type. Then browse for the desired file by placing the folder containing the file in the Look in slot. Find the file name, highlight it and it will appear in the File name slot. Then click on the OK button.
You will be able to crop only the right and bottom edges of thte image in MS Paint, but you can invert the image to crop the other two edges. Scroll the image in MS Paint so that the lower right corner of the imag is in the lower fight corner of the Paint screen. The look for the small black dots at the mid-point of either edge and drag it inward to perform a temporary cropping step. If it has brought in a proper amount, drag in the other black dot to perform another temporary cropping step.
Then invert the image by clicking on Image in the menu bar, then on Flip/Rotate in the drop-down menu. In the Flip and Rotate dialog box, select Rotate by angle in the radio box, and on 180o in the nest radio button , and click the OK button. With the image inverted, do the cropping steps as shown above. Note that while you are dragging in the black dots, you will find some numbers in the lower right corner of the Paint screen that will show you the image dimensions in pixels. You may have a target size in mind like 800 X 600, and MS Paint will let you achieve that size.
After cropping along these two sides, invert the image by doing the lfip and rotate process described above. Then make sure you do a Save As on the upright and cropped image. Fhis means you must give the file a name and a choose a folder in which to place it. The file will have a BMP file extension
Then you may want to convert the cropped image to a JPG format. When doing this, you may find that the image will appear dark and washed out. One way to correct for this is to increase the brightness and the contrast of the image before converting it back to the JPG image format. In Adobe programs and in Irfan View, increase the brightness by about 12 points and the contrast by about 15 points.
To crop in Irfan View, take the mouse pointer and drag a rectangle around the desired portion of the image and when satisfied that is a suitable crop, click on Edit, then on Crop. Remember that the image you are seeing is a temporary one and if you want to save it, you must take the steps to do so.
Cropping in Adobe programs follows a pattern of commands which are similar to one another, but the specifics may depend on the program and the version. You must file a selection called Trim & Size. In recent versions, you may start with Get & Fix photo, then to Rotate & Size, which should show Trim & Size in a drop-down menu. Click on Trim & size, and you will see a display with a heading of Trim and a set of three tabs, with the left tab highlighted which says Start here. Click on the next tab which says Trim. This will drop down a set of three icons which have captions saying Trim, OK, and Cancel. In the Trim icon, note that there is a dashed line that represents a cropping operation. Click within that dashed line. Then go to the image that appears in the Adobe screen an place the mouse cursor on the image. You will notice that the cursor is now a double crosshair pattern. This can be used to drag a rectangular frame around the image that you want to keep. You can make adjustments to the position of this frame by dragging on the black squares at any corner or any edge of the frame. When you are satisfied with the frame size and position, click on OK, and the temporary image will be cropped. The image must them be saved.
Comments on performing a screen capture of a PDF file
These comments will address a special case of a file viewer that treats zoom values in a different manner than most viewers. If you Copy a screen view of a PDF file presented by Adobes Acrobat Reader, it is not likely to show up in another viewer with an image size that you expect. Some background on this comment follows.
The Acrobat Reader has an indicator of zoom value which affects the image size presented on the screen. A user should also be aware that image file data may not be extractable from a PDF file by any simple means other than by a screen capture. Text data can be extracted by using the Text tool to enable the pointer to highlight the (entire span of horizontal) text lines of interest.
Regarding the zoom value selected in Acrobat Reader, note that most users have already underatken a 75 zoom of presentation on their screen by the choice of 800 X 600 pixels on their monitor, rather than 640 X 480, the default value. The implication of this is that most users will have to make a zoom setting of 133 in their Acrobat Reader for the material to show at full size, and to Copy at full size when doing a screen capture.
So, you ask, isnt this a simple matter and the answer is no. The normal way of setting a zoom value is to click on the View tool of the application and click on a menu value of zoom or to enter a custom number for a zoom value if the menu doesnt offer the value you want. Well, thats not the way it works in Acrobat Reader.
However, there are other features that can be used to obtain the desired custom zoom number. To achieve a zoom value of 133 takes a few steps that seem prohibitively difficult, but it can be done. A user may be better served by realizing that if their objective is to capture the detail of an image available in a PDF file, they may wish to do a screen capture at an Acrobat Reader zoom value near 133, and then perform a re-sizing step in an image modifying program.
If the desired image nearly fills an 8 ½ X 11 sheet of paper, you may find it advantageous to temporarily re-set your monitor zoom to a value as high as 1280 X 1024, so you acquire as many pixels as needed to give a good rendition of the picture.
Further details on how to proceed with the requisite steps to Copy an image from a screen capture of a PDF in Acrobat Reader when the page is displayed at 133 zoom are beyond the scope of this discussion. Let us just say that it imvolves temporary re-sizing of the monitor pixel setting, selecting the Navigation Pane in Acrobat Reader, selecting the Fit Width display of the page, and dragging the partition between the Navigation Pane and the displayed page to the right until a selected zoom size of 150 becomes 133
Previewing a collection of images in a folder by using temporary thumbnail images
You may wish to look at a collection of image files in a given folder to find what you are looking for. This can be a slow process if you open each file at full size and do the required point and click steps to display each image. Examples of large groups of image files may be archived photos from personal sources, or a collection of clip art images (often there are hundreds to thousands of images in a single folder).
There are some application programs that make this burden lighter by providing a group of temporary thumbnail images, some of which may be viewed on the screen as an array of displayed pictures. The process of moving forward or backward to the adjoining group is done by scrolling. The images are sequenced in alphanumeric order by image name.
Three applications known to have this capability are JASC Media Center Plus, ACDSee, and Irfan View. Media Center displays most of 24 thumbnail images at one time and Irfan View most of five thumbnail images at one time.
Here is a review found at CNET by Ken Feinstein:
A messy photo collection can cripple a fledgling photographer more quickly than bad lighting. Overwhelmed by more digital photos than you can handle? Consider whipping your collection into shape with ACDSee 4.0, a digital photo management tool that lets you view, organize, print, and share those amazing shots over the Internet. ACDSee is a great buy for digicam enthusiasts who don't plan to upgrade to Windows XP. However, if you spring for XP, don't spend $49.95 on this tool; you'll find most of ACDSee's features already tucked within Microsoft's new OS. Like PhotoPrint, ACDSee offers extensive tools for sharing photos on the Internet, but it really shines at helping prolific shooters organize their images.
Irfan View has a feature that lets you step quickly from one image file to the next at full image size by clicking on either of two arrows on the toolbar. Simply clicking on either mouse button will advance or retard the view to the next frame in alphabetic order within that folder, depending on whether you click on the left or the right button. When you do this, you will see the file name presented on the screen along with the image. This feature makes Irfan View a photo album viewer that can flip photos manually..
In addition, it serves as a multimedia player that can be operated in a few different modes, each of which are easy to set up. Irfan View automatically step through all the slides in a folder. To return to normal frame viewing, strike the ESC key.
It also has a slideshow feature that allows you to select the images to be shown from files on your hard drive. It creates a text file of the full path and file name, which can be played from the slideshow player.
A caveat on thumbnail presentations
A user should be aware that when using either of these applications for previewing a very large group of files in one folder, Windows, together with the the application program, will have the shortcoming of not having enough memory to accommodate the formation of each of the temporary image files as thumbnails. Thus, you may have gaps in the collection that will be displayed as thumbnails. If a user does much work with the selection of image files from folders containing large numbers of clip art images, it may behoove them to use file management techniques to organize files into folders of about 400 or fewer.
Another thing a user can anticipate is that if you place a large number of image files in temporary image form, like when previewing as thumbnail images, the application program may retain so much data in shared memory that the reserve capacity of system resources drop to a very low level. If this occurs, you may note unusual and sluggish behavior of your computer, like being unable to connect to your ISP. This situation can be corrected by re-booting your computer.
Visua and imagoWeb features
Visua and imagoWeb are speedy programs for viewing and converting your graphics files. The program supports a multitude of file formats, including JPEG, GIF, BMP, DIB, RLE, AVI, and WMF. Features include a TWAIN interface for linking to the scanning software, a thumbnail image viewer for previewing all the images in a given directory, print-preview capabilities, and more. New features include a wizard slide show, wizard batch-conversion, and HTML file creation capabilities that let you display images as thumbnails with links to the full size images. This software is in Italian and English.
Viewing images at full size in web browser
A feature is available in web browsers to resize the image that it presents to you in the screen. You can view the 2 megapixel digital camera images at a convenient size on the screen if this feature is enabled. This feature can be enabled or disabled. The default setting is for it to be enabled.
A user should be aware of this feature and should know if it is enabled or disabled. If a user plans to view and print images in an application other than the web browser, they may want to make sure that this feature is disabled, so they will see the image at full size and realize that this is the size it will appear in other viewers and the size that will be sent to the printer. Then they can determine the extent of re-sizing and cropping that is necessary for their purposes.
The setting for making this change is in the Internet Options dialog box on the page that opens with the Advanced tab, and in the Multimedia group, which is far down on this page. The small box beside Enable Automatic Image Resizing will have a check mark in it if this feature is enabled.
The Internet Options page can be found in Control Panel. It can also be found while in the internet browser by clicking on Tools in the toolbar. A drop-down menu will show Internet Options.
A user should also be aware that when you print from a web browser, you will print header and footer data and your margins will be determined by the margin settings of your browser. It can be cumbersome to alter these settings. They features are convenient for capturing information about where web data was gathered. They also affect how email messages are printed.
Viewers with a Zoom capability
You may find that there are benefits when using a viewer that has a zoom viewing ability. These viewers include Irfan View, ACDSee, and PhotoImpact by Ulead. This feature may be used to zoom out by a value that will provide a display of a large photo on your screen such that you dont have to scroll to see major parts of the photo.