Qt OpenCV Support Image Type 支持读写的图像格式

Qt 支持的图片格式如下：

Format	Description	Qt's support
BMP	Windows Bitmap	Read/write
GIF	Graphic Interchange Format (optional)	Read
JPG	Joint Photographic Experts Group	Read/write
JPEG	Joint Photographic Experts Group	Read/write
PNG	Portable Network Graphics	Read/write
PBM	Portable Bitmap	Read
PGM	Portable Graymap	Read
PPM	Portable Pixmap	Read/write
TIFF	Tagged Image File Format	Read/write
XBM	X11 Bitmap	Read/write
XPM	X11 Pixmap	Read/write

OpenCV 支持的图片格式如下：

    Windows bitmaps - *.bmp, *.dib (always supported)
    JPEG files - *.jpeg, *.jpg, *.jpe (see the Notes section)
    JPEG 2000 files - *.jp2 (see the Notes section)
    Portable Network Graphics - *.png (see the Notes section)
    Portable image format - *.pbm, *.pgm, *.ppm (always supported)
    Sun rasters - *.sr, *.ras (always supported)
    TIFF files - *.tiff, *.tif (see the Notes section)

下面是1024X768分辨率的图片在各种格式下的尺寸，参见这里。

图片格式	色彩位数	图片质量	文件大小（KB）	备注
bmp	8	-	769	-
bmp	24	-	2359	-
jpg	-	0%	104	-
jpg	-	25%	124	-
jpg	-	50%	156	-
jpg	-	75%	220	-
jpg	-	100%	639	-
gif	8	-	225	-
tiff	-	-	1880	-
png	-	-	868	用ACDSEE保存
png	1	-	73	用PhotoShop保存
png	6	-	194	用PhotoShop保存
png	7	-	267	用PhotoShop保存
png	8	-	332	用PhotoShop保存
png	24	-	895	用PhotoShop保存

从上表可以看出，jpg格式在图片大小和质量之间得到了很好的平衡；即使选择0%的图片质量，仍然可以接受，而图片大小只有104KB。